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Zafar H, Saier MH. An insider's perspective about the pathogenic relevance of gut bacterial transportomes. Microb Physiol 2024:000538779. [PMID: 38636461 DOI: 10.1159/000538779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Accepted: 04/04/2024] [Indexed: 04/20/2024]
Abstract
BACKGROUND The gut microbiome is integral to host health, hosting complex interactions between the host and numerous microbial species in the gastrointestinal tract. Key among the molecular mechanisms employed by gut bacteria are transportomes, consisting of diverse transport proteins crucial for bacterial adaptation to the dynamic, nutrient-rich environment of the mammalian gut. These transportomes facilitate the movement of a wide array of molecules, impacting both the host and the microbial community. SUMMARY This communication explores the significance of transportomes in gut bacteria, focusing on their role in nutrient acquisition, competitive interactions among microbes, and potential pathogenicity. It delves into the transportomes of key gut bacterial species like E. coli, Salmonella, Bacteroides, Lactobacillus, Clostridia, and Bifidobacterium, examining the functions of predicted transport proteins. The overview synthesizes recent research efforts, highlighting how these transportomes influence host-microbe interactions and contribute to the microbial ecology of the gut. KEY MESSAGES Transportomes are vital for the survival and adaptation of bacteria in the gut, enabling the import and export of various nutrients and molecules. The complex interplay of transport proteins not only supports bacterial growth and competition but also has implications for host health, potentially contributing to pathogenic processes. Understanding the pathogenic potential of transportomes in major gut bacterial species provides insights into gut health and disease, offering avenues for future research and therapeutic strategies.
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2
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Kopkowski PW, Zhang Z, Saier MH. The effect of DNA-binding proteins on insertion sequence element transposition upstream of the bgl operon in Escherichia coli. Front Microbiol 2024; 15:1388522. [PMID: 38666260 PMCID: PMC11043490 DOI: 10.3389/fmicb.2024.1388522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Accepted: 03/22/2024] [Indexed: 04/28/2024] Open
Abstract
The bglGFB operon in Escherichia coli K-12 strain BW25113, encoding the proteins necessary for the uptake and metabolism of β-glucosides, is normally not expressed. Insertion of either IS1 or IS5 upstream of the bgl promoter activates expression of the operon only when the cell is starving in the presence of a β-glucoside, drastically increasing transcription and allowing the cell to survive and grow using this carbon source. Details surrounding the exact mechanism and regulation of the IS insertional event remain unclear. In this work, the role of several DNA-binding proteins in how they affect the rate of insertion upstream of bgl are examined via mutation assays and protocols measuring transcription. Both Crp and IHF exert a positive effect on insertional Bgl+ mutations when present, active, and functional in the cell. Our results characterize IHF's effect in conjunction with other mutations, show that IHF's effect on IS insertion into bgl also affects other operons, and indicate that it may exert its effect by binding to and altering the DNA conformation of IS1 and IS5 in their native locations, rather than by directly influencing transposase gene expression. In contrast, the cAMP-CRP complex acts directly upon the bgl operon by binding upstream of the promoter, presumably altering local DNA into a conformation that enhances IS insertion.
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Affiliation(s)
| | - Zhongge Zhang
- Department of Molecular Biology, School of Biological Sciences, University of California, San Diego, La Jolla, CA, United States
| | - Milton H. Saier
- Department of Molecular Biology, School of Biological Sciences, University of California, San Diego, La Jolla, CA, United States
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3
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Zhang Z, Huo J, Velo J, Zhou H, Flaherty A, Saier MH. Comprehensive Characterization of fucAO Operon Activation in Escherichia coli. Int J Mol Sci 2024; 25:3946. [PMID: 38612757 PMCID: PMC11011485 DOI: 10.3390/ijms25073946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Revised: 03/26/2024] [Accepted: 03/29/2024] [Indexed: 04/14/2024] Open
Abstract
Wildtype Escherichia coli cells cannot grow on L-1,2-propanediol, as the fucAO operon within the fucose (fuc) regulon is thought to be silent in the absence of L-fucose. Little information is available concerning the transcriptional regulation of this operon. Here, we first confirm that fucAO operon expression is highly inducible by fucose and is primarily attributable to the upstream operon promoter, while the fucO promoter within the 3'-end of fucA is weak and uninducible. Using 5'RACE, we identify the actual transcriptional start site (TSS) of the main fucAO operon promoter, refuting the originally proposed TSS. Several lines of evidence are provided showing that the fucAO locus is within a transcriptionally repressed region on the chromosome. Operon activation is dependent on FucR and Crp but not SrsR. Two Crp-cAMP binding sites previously found in the regulatory region are validated, where the upstream site plays a more critical role than the downstream site in operon activation. Furthermore, two FucR binding sites are identified, where the downstream site near the first Crp site is more important than the upstream site. Operon transcription relies on Crp-cAMP to a greater degree than on FucR. Our data strongly suggest that FucR mainly functions to facilitate the binding of Crp to its upstream site, which in turn activates the fucAO promoter by efficiently recruiting RNA polymerase.
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Affiliation(s)
- Zhongge Zhang
- Department of Molecular Biology, School of Biological Sciences, University of California at San Diego, 9500 Gilman Dr, La Jolla, CA 92093-0116, USA; (J.H.); (J.V.); (A.F.)
| | | | | | | | | | - Milton H. Saier
- Department of Molecular Biology, School of Biological Sciences, University of California at San Diego, 9500 Gilman Dr, La Jolla, CA 92093-0116, USA; (J.H.); (J.V.); (A.F.)
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Hendargo KJ, Patel AO, Chukwudozie OS, Moreno-Hagelsieb G, Christen JA, Medrano-Soto A, Saier MH. Sequence Similarity among Structural Repeats in the Piezo Family of Mechanosensitive Ion Channels. Microb Physiol 2023; 33:49-62. [PMID: 37321192 DOI: 10.1159/000531468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Accepted: 06/05/2023] [Indexed: 06/17/2023]
Abstract
Members of the Piezo family of mechanically activated cation channels are involved in multiple physiological processes in higher eukaryotes, including vascular development, cell differentiation, touch perception, hearing, and more, but they are also common in single-celled eukaryotic microorganisms. Mutations in these proteins in humans are associated with a variety of diseases, such as colorectal adenomatous polyposis, dehydrated hereditary stomatocytosis, and hereditary xerocytosis. Available 3D structures for Piezo proteins show nine regions of four transmembrane segments each that have the same fold. Despite the remarkable similarity among the nine characteristic structural repeats in the family, no significant sequence similarity among them has been reported. Using bioinformatics approaches and the Transporter Classification Database (TCDB) as reference, we reliably identified sequence similarity among repeats based on four lines of evidence: (1) hidden Markov model-profile similarities across repeats at the family level, (2) pairwise sequence similarities between different repeats across Piezo homologs, (3) Piezo-specific conserved sequence signatures that consistently identify the same regions across repeats, and (4) conserved residues that maintain the same orientation and location in 3D space.
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Affiliation(s)
- Kevin J Hendargo
- Department of Molecular Biology, School of Biological Sciences, University of California, San Diego, California, USA
| | - Ashay O Patel
- Department of Molecular Biology, School of Biological Sciences, University of California, San Diego, California, USA
| | - Onyeka S Chukwudozie
- Department of Molecular Biology, School of Biological Sciences, University of California, San Diego, California, USA
| | | | - J Andres Christen
- Departamento de Probabilidad y Estadística, Centro de Investigación en Matemáticas, CIMAT, Guanajuato, Mexico
| | - Arturo Medrano-Soto
- Department of Molecular Biology, School of Biological Sciences, University of California, San Diego, California, USA
| | - Milton H Saier
- Department of Molecular Biology, School of Biological Sciences, University of California, San Diego, California, USA
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5
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Rodionova IA, Hosseinnia A, Kim S, Goodacre N, Zhang L, Zhang Z, Palsson B, Uetz P, Babu M, Saier MH. E. coli allantoinase is activated by the downstream metabolic enzyme, glycerate kinase, and stabilizes the putative allantoin transporter by direct binding. Sci Rep 2023; 13:7345. [PMID: 37147430 PMCID: PMC10163214 DOI: 10.1038/s41598-023-31812-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Accepted: 03/17/2023] [Indexed: 05/07/2023] Open
Abstract
Allantoin is a good source of ammonium for many organisms, and in Escherichia coli it is utilized under anaerobic conditions. We provide evidence that allantoinase (AllB) is allosterically activated by direct binding of the allantoin catabolic enzyme, glycerate 2-kinase (GlxK) in the presence of glyoxylate. Glyoxylate is known to be an effector of the AllR repressor which regulates the allantoin utilization operons in E. coli. AllB has low affinity for allantoin, but its activation by GlxK leads to increased affinity for its substrate. We also show that the predicted allantoin transporter YbbW (re-named AllW) has allantoin specificity and the protein-protein interaction with AllB. Our results show that the AllB-dependent allantoin degradative pathway is subject to previously unrecognized regulatory mechanisms involving direct protein-protein interactions.
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Affiliation(s)
- Irina A Rodionova
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, CA, 92093, USA.
- Department of Bioengineering, Division of Engineering, University of California at San Diego, La Jolla, CA, 92093-0116, USA.
| | - Ali Hosseinnia
- Department of Biochemistry, University of Regina, Regina, SK, S4S 0A2, Canada
| | - Sunyoung Kim
- Department of Biochemistry, University of Regina, Regina, SK, S4S 0A2, Canada
| | - Norman Goodacre
- Center for the Study of Biological Complexity, Virginia Commonwealth University, Richmond, VA, 23284, USA
| | - Li Zhang
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, CA, 92093, USA
- College of Food Science and Engineering, Ocean University of China, Yushan Road, Shinan District, Qingdao, 266003, China
| | - Zhongge Zhang
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, CA, 92093, USA
| | - Bernhard Palsson
- Department of Bioengineering, Division of Engineering, University of California at San Diego, La Jolla, CA, 92093-0116, USA
- Department of Pediatrics, University of California San Diego, La Jolla, CA, 92093, USA
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2800, Lyngby, Denmark
| | - Peter Uetz
- Center for the Study of Biological Complexity, Virginia Commonwealth University, Richmond, VA, 23284, USA
| | - Mohan Babu
- Department of Biochemistry, University of Regina, Regina, SK, S4S 0A2, Canada
| | - Milton H Saier
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, CA, 92093, USA.
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Zafar H, Saier MH. Understanding the Relationship of the Human Bacteriome with COVID-19 Severity and Recovery. Cells 2023; 12:cells12091213. [PMID: 37174613 PMCID: PMC10177376 DOI: 10.3390/cells12091213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 04/05/2023] [Accepted: 04/11/2023] [Indexed: 05/15/2023] Open
Abstract
The Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) first emerged in 2019 in China and has resulted in millions of human morbidities and mortalities across the globe. Evidence has been provided that this novel virus originated in animals, mutated, and made the cross-species jump to humans. At the time of this communication, the Coronavirus disease (COVID-19) may be on its way to an endemic form; however, the threat of the virus is more for susceptible (older and immunocompromised) people. The human body has millions of bacterial cells that influence health and disease. As a consequence, the bacteriomes in the human body substantially influence human health and disease. The bacteriomes in the body and the immune system seem to be in constant association during bacterial and viral infections. In this review, we identify various bacterial spp. In major bacteriomes (oral, nasal, lung, and gut) of the body in healthy humans and compare them with dysbiotic bacteriomes of COVID-19 patients. We try to identify key bacterial spp. That have a positive effect on the functionality of the immune system and human health. These select bacterial spp. Could be used as potential probiotics to counter or prevent COVID-19 infections. In addition, we try to identify key metabolites produced by probiotic bacterial spp. That could have potential anti-viral effects against SARS-CoV-2. These metabolites could be subject to future therapeutic trials to determine their anti-viral efficacies.
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Affiliation(s)
- Hassan Zafar
- Department of Molecular Biology, School of Biological Sciences, University of California, San Diego, CA 92093-0116, USA
- Central European Institute of Technology, Masaryk University, 625 00 Brno, Czech Republic
| | - Milton H Saier
- Department of Molecular Biology, School of Biological Sciences, University of California, San Diego, CA 92093-0116, USA
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Tran D, Zhang Z, Lam KJK, Saier MH. Effects of Global and Specific DNA-Binding Proteins on Transcriptional Regulation of the E. coli bgl Operon. Int J Mol Sci 2022; 23:ijms231810343. [PMID: 36142257 PMCID: PMC9499468 DOI: 10.3390/ijms231810343] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 08/18/2022] [Accepted: 08/31/2022] [Indexed: 11/16/2022] Open
Abstract
Using reporter gene (lacZ) transcriptional fusions, we examined the transcriptional dependencies of the bgl promoter (Pbgl) and the entire operon regulatory region (Pbgl-bglG) on eight transcription factors as well as the inducer, salicin, and an IS5 insertion upstream of Pbgl. Crp-cAMP is the primary activator of both Pbgl and the bgl operon, while H-NS is a strong dominant operon repressor but only a weak repressor of Pbgl. H-NS may exert its repressive effect by looping the DNA at two binding sites. StpA is a relatively weak repressor in the absence of H-NS, while Fis also has a weak repressive effect. Salicin has no effect on Pbgl activity but causes a 30-fold induction of bgl operon expression. Induction depends on the activity of the BglF transporter/kinase. IS5 insertion has only a moderate effect on Pbgl but causes a much greater activation of the bgl operon expression by preventing the full repressive effects of H-NS and StpA. While several other transcription factors (BglJ, RcsB, and LeuO) have been reported to influence bgl operon transcription when overexpressed, they had little or no effect when present at wild type levels. These results indicate the important transcriptional regulatory mechanisms operative on the bgl operon in E. coli.
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Rodionova IA, Gao Y, Monk J, Hefner Y, Wong N, Szubin R, Lim HG, Rodionov DA, Zhang Z, Saier MH, Palsson BO. A systems approach discovers the role and characteristics of seven LysR type transcription factors in Escherichia coli. Sci Rep 2022; 12:7274. [PMID: 35508583 PMCID: PMC9068703 DOI: 10.1038/s41598-022-11134-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 04/14/2022] [Indexed: 11/24/2022] Open
Abstract
Although Escherichia coli K-12 strains represent perhaps the best known model bacteria, we do not know the identity or functions of all of their transcription factors (TFs). It is now possible to systematically discover the physiological function of TFs in E. coli BW25113 using a set of synergistic methods; including ChIP-exo, growth phenotyping, conserved gene clustering, and transcriptome analysis. Among 47 LysR-type TFs (LTFs) found on the E. coli K-12 genome, many regulate nitrogen source utilization or amino acid metabolism. However, 19 LTFs remain unknown. In this study, we elucidated the regulation of seven of these 19 LTFs: YbdO, YbeF, YcaN, YbhD, YgfI, YiaU, YneJ. We show that: (1) YbdO (tentatively re-named CitR) regulation has an effect on bacterial growth at low pH with citrate supplementation. CitR is a repressor of the ybdNM operon and is implicated in the regulation of citrate lyase genes (citCDEFG); (2) YgfI (tentatively re-named DhfA) activates the dhaKLM operon that encodes the phosphotransferase system, DhfA is involved in formate, glycerol and dihydroxyacetone utilization; (3) YiaU (tentatively re-named LpsR) regulates the yiaT gene encoding an outer membrane protein, and waaPSBOJYZU operon is also important in determining cell density at the stationary phase and resistance to oxacillin microaerobically; (4) YneJ, re-named here as PtrR, directly regulates the expression of the succinate-semialdehyde dehydrogenase, Sad (also known as YneI), and is a predicted regulator of fnrS (a small RNA molecule). PtrR is important for bacterial growth in the presence of l-glutamate and putrescine as nitrogen/energy sources; and (5) YbhD and YcaN regulate adjacent y-genes on the genome. We have thus established the functions for four LTFs and identified the target genes for three LTFs.
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Affiliation(s)
- Irina A Rodionova
- Department of Bioengineering, University of California San Diego, La Jolla, CA, 92093-0116, USA. .,Division of Biological Sciences, Department of Molecular Biology, University of California San Diego, La Jolla, CA, 92093-0116, USA.
| | - Ye Gao
- Department of Bioengineering, University of California San Diego, La Jolla, CA, 92093-0116, USA.,Division of Biological Sciences, Department of Molecular Biology, University of California San Diego, La Jolla, CA, 92093-0116, USA
| | - Jonathan Monk
- Department of Bioengineering, University of California San Diego, La Jolla, CA, 92093-0116, USA
| | - Ying Hefner
- Department of Bioengineering, University of California San Diego, La Jolla, CA, 92093-0116, USA
| | - Nicholas Wong
- Division of Biological Sciences, Department of Molecular Biology, University of California San Diego, La Jolla, CA, 92093-0116, USA
| | - Richard Szubin
- Department of Bioengineering, University of California San Diego, La Jolla, CA, 92093-0116, USA
| | - Hyun Gyu Lim
- Department of Bioengineering, University of California San Diego, La Jolla, CA, 92093-0116, USA
| | - Dmitry A Rodionov
- Sanford-Burnham-Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA
| | - Zhongge Zhang
- Division of Biological Sciences, Department of Molecular Biology, University of California San Diego, La Jolla, CA, 92093-0116, USA
| | - Milton H Saier
- Division of Biological Sciences, Department of Molecular Biology, University of California San Diego, La Jolla, CA, 92093-0116, USA
| | - Bernhard O Palsson
- Department of Bioengineering, University of California San Diego, La Jolla, CA, 92093-0116, USA. .,Department of Pediatrics, University of California San Diego, La Jolla, CA, 92093, USA. .,Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2800, Lyngby, Denmark.
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Zafar H, Saier MH. Comparative Analyses of the Transport Proteins Encoded within the Genomes of nine Bifidobacterium Species. Microb Physiol 2022; 32:30-44. [PMID: 34555832 PMCID: PMC8940750 DOI: 10.1159/000518954] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2021] [Accepted: 08/02/2021] [Indexed: 01/03/2023]
Abstract
The human microbiome influences human health in both negative and positive ways. Studies on the transportomes of these organisms yield information that may be utilized for various purposes, including the identification of novel drug targets and the manufacture of improved probiotic strains. Moreover, these genomic analyses help to improve our understanding of the physiology and metabolic capabilities of these organisms. The present study is a continuation of our studies on the transport proteins of the major gut microbes. Bifidobacterium species are essential members of the human gut microbiome, and they initiate colonization of the gut at birth, providing health benefits that last a lifetime. In this study we analyze the transportomes of nine bifidobacterial species: B. adolescentis, B. animalis, B. bifidum, B. breve, B. catenulatum, B. dentium, B. longum subsp. infantis, B. longum subsp. longum, and B. pseudocatenulatum. All of these species have proven probiotic characteristics and exert beneficial effects on human health. Surprisingly, we found that all nine of these species have similar pore-forming toxins and drug exporters that may play roles in pathogenesis. These species have transporters for amino acids, carbohydrates, and proteins, essential for their organismal lifestyles and adaption to their respective ecological niches. The strictly probiotic species, B. bifidum, however, contains fewer such transporters, thus indicative of limited interactions with host cells and other gut microbial counterparts. The results of this study were compared with those of our previous studies on the transportomes of multiple species of Bacteroides, Escherichia coli/Salmonella, and Lactobacillus. Overall, bifidobacteria have larger transportomes (based on percentages of total proteins) than the previously examined groups of bacterial species, with a preference for primary active transport systems over secondary carriers. Taken together, these results provide useful information about the physiologies and pathogenic potentials of these probiotic organisms as reflected by their transportomes.
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Affiliation(s)
- Hassan Zafar
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, CA 92093-0116.,Central European Institute of Technology, Masaryk University, Kamenice 5, Brno, 625 00, Czech Republic.,Corresponding Authors HZ: Tel: +420773283624, ; MS: Tel: +1 858 534 4084, Fax: +1 858 534 7108,
| | - Milton H. Saier
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, CA 92093-0116.,Corresponding Authors HZ: Tel: +420773283624, ; MS: Tel: +1 858 534 4084, Fax: +1 858 534 7108,
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10
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Tyler D, Hendargo KJ, Medrano-Soto A, Saier MH. Discovery and Characterization of the Phospholemman/SIMP/Viroporin Superfamily. Microb Physiol 2022; 32:83-94. [PMID: 35152214 PMCID: PMC9355910 DOI: 10.1159/000521947] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2021] [Accepted: 01/11/2022] [Indexed: 11/19/2022]
Abstract
Using bioinformatic approaches, we present evidence of distant relatedness among the Ephemerovirus Viroporin family, the Rhabdoviridae Putative Viroporin U5 family, the Phospholemman family, and the Small Integral Membrane Protein family. Our approach is based on the transitivity property of homology complemented with five validation criteria: (1) significant sequence similarity and alignment coverage, (2) compatibility of topology of transmembrane segments, (3) overlap of hydropathy profiles, (4) conservation of protein domains, and (5) conservation of sequence motifs. Our results indicate that Pfam protein domains PF02038 and PF15831 can be found in or projected onto members of all four families. In addition, we identified a 26-residue motif conserved across the superfamily. This motif is characterized by hydrophobic residues that help anchor the protein to the membrane and charged residues that constitute phosphorylation sites. In addition, all members of the four families with annotated function are either responsible for or affect the transport of ions into and/or out of the cell. Taken together, these results justify the creation of the novel Phospholemman/SIMP/Viroporin superfamily. Given that transport proteins can be found not just in cells, but also in viruses, the ability to relate viroporin protein families with their eukaryotic and bacterial counterparts is an important development in this superfamily.
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Affiliation(s)
| | | | - Arturo Medrano-Soto
- Corresponding Authors: Milton H. Saier, Jr. & Arturo
Medrano-Soto, Department of Molecular Biology, Division of Biological Sciences.,
University of California, San Diego., 9500 Gilman Drive #0116, La Jolla,
California. 92093-0116, Tel: 858-534-4084, &
| | - Milton H. Saier
- Corresponding Authors: Milton H. Saier, Jr. & Arturo
Medrano-Soto, Department of Molecular Biology, Division of Biological Sciences.,
University of California, San Diego., 9500 Gilman Drive #0116, La Jolla,
California. 92093-0116, Tel: 858-534-4084, &
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11
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Chowdhury S, Hepper S, Lodi MK, Saier MH, Uetz P. The Protein Interactome of Glycolysis in Escherichia coli. Proteomes 2021; 9:proteomes9020016. [PMID: 33917325 PMCID: PMC8167557 DOI: 10.3390/proteomes9020016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 03/31/2021] [Accepted: 04/02/2021] [Indexed: 11/16/2022] Open
Abstract
Glycolysis is regulated by numerous mechanisms including allosteric regulation, post-translational modification or protein-protein interactions (PPI). While glycolytic enzymes have been found to interact with hundreds of proteins, the impact of only some of these PPIs on glycolysis is well understood. Here we investigate which of these interactions may affect glycolysis in E. coli and possibly across numerous other bacteria, based on the stoichiometry of interacting protein pairs (from proteomic studies) and their conservation across bacteria. We present a list of 339 protein-protein interactions involving glycolytic enzymes but predict that ~70% of glycolytic interactors are not present in adequate amounts to have a significant impact on glycolysis. Finally, we identify a conserved but uncharacterized subset of interactions that are likely to affect glycolysis and deserve further study.
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Affiliation(s)
- Shomeek Chowdhury
- Integrative Life Sciences, Virginia Commonwealth University, 1000 West Cary Street, Richmond, VA 23284, USA; or
| | - Stephen Hepper
- Center for the Study of Biological Complexity, Virginia Commonwealth University, Richmond, VA 23284, USA; (S.H.); (M.K.L.)
| | - Mudassir K. Lodi
- Center for the Study of Biological Complexity, Virginia Commonwealth University, Richmond, VA 23284, USA; (S.H.); (M.K.L.)
| | - Milton H. Saier
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, CA 92093, USA;
| | - Peter Uetz
- Center for the Study of Biological Complexity, Virginia Commonwealth University, Richmond, VA 23284, USA; (S.H.); (M.K.L.)
- Correspondence:
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12
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Russum S, Lam KJK, Wong NA, Iddamsetty V, Hendargo KJ, Wang J, Dubey A, Zhang Y, Medrano-Soto A, Saier MH. Comparative population genomic analyses of transporters within the Asgard archaeal superphylum. PLoS One 2021; 16:e0247806. [PMID: 33770091 PMCID: PMC7997004 DOI: 10.1371/journal.pone.0247806] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 02/15/2021] [Indexed: 01/02/2023] Open
Abstract
Upon discovery of the first archaeal species in the 1970s, life has been subdivided into three domains: Eukarya, Archaea, and Bacteria. However, the organization of the three-domain tree of life has been challenged following the discovery of archaeal lineages such as the TACK and Asgard superphyla. The Asgard Superphylum has emerged as the closest archaeal ancestor to eukaryotes, potentially improving our understanding of the evolution of life forms. We characterized the transportomes and their substrates within four metagenome-assembled genomes (MAGs), that is, Odin-, Thor-, Heimdall- and Loki-archaeota as well as the fully sequenced genome of Candidatus Prometheoarchaeum syntrophicum strain MK-D1 that belongs to the Loki phylum. Using the Transporter Classification Database (TCDB) as reference, candidate transporters encoded within the proteomes were identified based on sequence similarity, alignment coverage, compatibility of hydropathy profiles, TMS topologies and shared domains. Identified transport systems were compared within the Asgard superphylum as well as within dissimilar eukaryotic, archaeal and bacterial organisms. From these analyses, we infer that Asgard organisms rely mostly on the transport of substrates driven by the proton motive force (pmf), the proton electrochemical gradient which then can be used for ATP production and to drive the activities of secondary carriers. The results indicate that Asgard archaea depend heavily on the uptake of organic molecules such as lipid precursors, amino acids and their derivatives, and sugars and their derivatives. Overall, the majority of the transporters identified are more similar to prokaryotic transporters than eukaryotic systems although several instances of the reverse were documented. Taken together, the results support the previous suggestions that the Asgard superphylum includes organisms that are largely mixotrophic and anaerobic but more clearly define their metabolic potential while providing evidence regarding their relatedness to eukaryotes.
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Affiliation(s)
- Steven Russum
- Division of Biological Sciences, Department of Molecular Biology, University of California at San Diego, La Jolla, CA, United States of America
| | - Katie Jing Kay Lam
- Division of Biological Sciences, Department of Molecular Biology, University of California at San Diego, La Jolla, CA, United States of America
| | - Nicholas Alan Wong
- Division of Biological Sciences, Department of Molecular Biology, University of California at San Diego, La Jolla, CA, United States of America
| | - Vasu Iddamsetty
- Division of Biological Sciences, Department of Molecular Biology, University of California at San Diego, La Jolla, CA, United States of America
| | - Kevin J. Hendargo
- Division of Biological Sciences, Department of Molecular Biology, University of California at San Diego, La Jolla, CA, United States of America
| | - Jianing Wang
- Division of Biological Sciences, Department of Molecular Biology, University of California at San Diego, La Jolla, CA, United States of America
| | - Aditi Dubey
- Division of Biological Sciences, Department of Molecular Biology, University of California at San Diego, La Jolla, CA, United States of America
| | - Yichi Zhang
- Division of Biological Sciences, Department of Molecular Biology, University of California at San Diego, La Jolla, CA, United States of America
| | - Arturo Medrano-Soto
- Division of Biological Sciences, Department of Molecular Biology, University of California at San Diego, La Jolla, CA, United States of America
- * E-mail: (MHS); (AMS)
| | - Milton H. Saier
- Division of Biological Sciences, Department of Molecular Biology, University of California at San Diego, La Jolla, CA, United States of America
- * E-mail: (MHS); (AMS)
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13
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Wong NA, Saier MH. The SARS-Coronavirus Infection Cycle: A Survey of Viral Membrane Proteins, Their Functional Interactions and Pathogenesis. Int J Mol Sci 2021; 22:1308. [PMID: 33525632 PMCID: PMC7865831 DOI: 10.3390/ijms22031308] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 01/21/2021] [Accepted: 01/22/2021] [Indexed: 02/07/2023] Open
Abstract
Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) is a novel epidemic strain of Betacoronavirus that is responsible for the current viral pandemic, coronavirus disease 2019 (COVID-19), a global health crisis. Other epidemic Betacoronaviruses include the 2003 SARS-CoV-1 and the 2009 Middle East Respiratory Syndrome Coronavirus (MERS-CoV), the genomes of which, particularly that of SARS-CoV-1, are similar to that of the 2019 SARS-CoV-2. In this extensive review, we document the most recent information on Coronavirus proteins, with emphasis on the membrane proteins in the Coronaviridae family. We include information on their structures, functions, and participation in pathogenesis. While the shared proteins among the different coronaviruses may vary in structure and function, they all seem to be multifunctional, a common theme interconnecting these viruses. Many transmembrane proteins encoded within the SARS-CoV-2 genome play important roles in the infection cycle while others have functions yet to be understood. We compare the various structural and nonstructural proteins within the Coronaviridae family to elucidate potential overlaps and parallels in function, focusing primarily on the transmembrane proteins and their influences on host membrane arrangements, secretory pathways, cellular growth inhibition, cell death and immune responses during the viral replication cycle. We also offer bioinformatic analyses of potential viroporin activities of the membrane proteins and their sequence similarities to the Envelope (E) protein. In the last major part of the review, we discuss complement, stimulation of inflammation, and immune evasion/suppression that leads to CoV-derived severe disease and mortality. The overall pathogenesis and disease progression of CoVs is put into perspective by indicating several stages in the resulting infection process in which both host and antiviral therapies could be targeted to block the viral cycle. Lastly, we discuss the development of adaptive immunity against various structural proteins, indicating specific vulnerable regions in the proteins. We discuss current CoV vaccine development approaches with purified proteins, attenuated viruses and DNA vaccines.
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Affiliation(s)
- Nicholas A. Wong
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, CA 92093-0116, USA
| | - Milton H. Saier
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, CA 92093-0116, USA
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14
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Saier MH, Reddy VS, Moreno-Hagelsieb G, Hendargo KJ, Zhang Y, Iddamsetty V, Lam KJK, Tian N, Russum S, Wang J, Medrano-Soto A. The Transporter Classification Database (TCDB): 2021 update. Nucleic Acids Res 2021; 49:D461-D467. [PMID: 33170213 PMCID: PMC7778945 DOI: 10.1093/nar/gkaa1004] [Citation(s) in RCA: 139] [Impact Index Per Article: 46.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 10/12/2020] [Accepted: 10/15/2020] [Indexed: 12/20/2022] Open
Abstract
The Transporter Classification Database (TCDB; tcdb.org) is a freely accessible reference resource, which provides functional, structural, mechanistic, medical and biotechnological information about transporters from organisms of all types. TCDB is the only transport protein classification database adopted by the International Union of Biochemistry and Molecular Biology (IUBMB) and now (October 1, 2020) consists of 20 653 proteins classified in 15 528 non-redundant transport systems with 1567 tabulated 3D structures, 18 336 reference citations describing 1536 transporter families, of which 26% are members of 82 recognized superfamilies. Overall, this is an increase of over 50% since the last published update of the database in 2016. This comprehensive update of the database contents and features include (i) adoption of a chemical ontology for substrates of transporters, (ii) inclusion of new superfamilies, (iii) a domain-based characterization of transporter families for the identification of new members as well as functional and evolutionary relationships between families, (iv) development of novel software to facilitate curation and use of the database, (v) addition of new subclasses of transport systems including 11 novel types of channels and 3 types of group translocators and (vi) the inclusion of many man-made (artificial) transmembrane pores/channels and carriers.
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Affiliation(s)
- Milton H Saier
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, CA 92093-0116, USA
| | - Vamsee S Reddy
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, CA 92093-0116, USA
| | | | - Kevin J Hendargo
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, CA 92093-0116, USA
| | - Yichi Zhang
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, CA 92093-0116, USA
| | - Vasu Iddamsetty
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, CA 92093-0116, USA
| | - Katie Jing Kay Lam
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, CA 92093-0116, USA
| | - Nuo Tian
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, CA 92093-0116, USA
| | - Steven Russum
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, CA 92093-0116, USA
| | - Jianing Wang
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, CA 92093-0116, USA
| | - Arturo Medrano-Soto
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, CA 92093-0116, USA
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15
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Abstract
The functional diversity of the mammalian intestinal microbiome far exceeds that of the host organism, and microbial genes contribute substantially to the well-being of the host. However, beneficial gut organisms can also be pathogenic when present in the gut or other locations in the body. Among dominant beneficial bacteria are several species of Bacteroides, which metabolize polysaccharides and oligosaccharides, providing nutrition and vitamins to the host and other intestinal microbial residents. These topics and the specific organismal and molecular interactions that are known to be responsible for the beneficial and detrimental effects of Bacteroides species in humans comprise the focus of this review. The complexity of these interactions will be revealed.
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Affiliation(s)
- Hassan Zafar
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, USA
- Department of Microbiology and Molecular Genetics, Faculty of Life Sciences, University of Okara,Okara, PunjabPakistan
| | - Milton H. Saier
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, USA
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16
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Zafar H, Saier MH. Comparative Genomics of the Transport Proteins of Ten Lactobacillus Strains. Genes (Basel) 2020; 11:genes11101234. [PMID: 33096690 PMCID: PMC7593918 DOI: 10.3390/genes11101234] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2020] [Revised: 10/13/2020] [Accepted: 10/16/2020] [Indexed: 12/24/2022] Open
Abstract
The genus Lactobacillus includes species that may inhabit different anatomical locations in the human body, but the greatest percentage of its species are inhabitants of the gut. Lactobacilli are well known for their probiotic characteristics, although some species may become pathogenic and exert negative effects on human health. The transportome of an organism consists of the sum of the transport proteins encoded within its genome, and studies on the transportome help in the understanding of the various physiological processes taking place in the cell. In this communication we analyze the transport proteins and predict probable substrate specificities of ten Lactobacillus strains. Six of these strains (L. brevis, L. bulgaricus, L. crispatus, L. gasseri, L. reuteri, and L. ruminis) are currently believed to be only probiotic (OP). The remaining four strains (L. acidophilus, L. paracasei, L. planatarum, and L. rhamnosus) can play dual roles, being both probiotic and pathogenic (PAP). The characteristics of the transport systems found in these bacteria were compared with strains (E. coli, Salmonella, and Bacteroides) from our previous studies. Overall, the ten lactobacilli contain high numbers of amino acid transporters, but the PAP strains contain higher number of sugar, amino acid and peptide transporters as well as drug exporters than their OP counterparts. Moreover, some of the OP strains contain pore-forming toxins and drug exporters similar to those of the PAP strains, thus indicative of yet unrecognized pathogenic potential. The transportomes of the lactobacilli seem to be finely tuned according to the extracellular and probiotic lifestyles of these organisms. Taken together, the results of this study help to reveal the physiological and pathogenic potential of common prokaryotic residents in the human body.
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Affiliation(s)
- Hassan Zafar
- Department of Molecular Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093-0116, USA
- Department of Microbiology and Molecular Genetics, Faculty of Life Sciences, University of Okara, Okara, Punjab 56300, Pakistan
- Correspondence: (H.Z.); (M.H.S.J.); Tel.: +1-858-534-4084 (M.H.S.J.); Fax: +1-858-534-7108 (M.H.S.J.)
| | - Milton H. Saier
- Department of Molecular Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093-0116, USA
- Correspondence: (H.Z.); (M.H.S.J.); Tel.: +1-858-534-4084 (M.H.S.J.); Fax: +1-858-534-7108 (M.H.S.J.)
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17
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Aboulwafa M, Zhang Z, Saier MH. Protein-Protein Interactions in the Cytoplasmic Membrane of Escherichia coli: Influence of the Overexpression of Diverse Transporter-Encoding Genes on the Activities of PTS Sugar Uptake Systems. Microb Physiol 2020; 30:36-49. [PMID: 32998150 DOI: 10.1159/000510257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Accepted: 07/16/2020] [Indexed: 11/19/2022]
Abstract
The prokaryotic phosphoenolpyruvate (PEP):sugar phosphotransferase system (PTS) concomitantly transports and phosphorylates its substrate sugars. In a recent publication, we provided evidence that protein-protein interactions of the fructose-specific integral membrane transporter (FruAB) with other PTS sugar group translocators regulate the activities of the latter systems in vivo and sometimes in vitro. In this communication, we examine the consequences of the overexpression of several different transport systems on the activities of selected PTS and non-PTS permeases. We report that high levels of these transport systems enhance the in vivo activities of several other systems in a fairly specific fashion. Thus, (1) overexpression of ptsG (glucose porter) selectively enhanced mannitol, N-acetylglucosamine, and 2-deoxyglucose (2DG) uptake rates; (2) overexpression of mtlA (mannitol porter) promoted methyl α-glucoside (αMG) and 2DG uptake; (3) manYZ (but not manY alone) (mannose porter) overexpression enhanced αMG uptake; (4) galP (galactose porter) overexpression enhanced mannitol and αMG uptake; and (5) ansP (asparagine porter) overexpression preferentially enhanced αMG and 2DG uptake, all presumably as a result of direct protein-protein interactions. Thus, it appears that high level production of several integral membrane permeases enhances sugar uptake rates, with the PtsG and ManXYZ systems being most consistently stimulated, but the MtlA and NagE systems being more selectively stimulated and to a lesser extent. Neither enhanced expression nor in vitro PEP-dependent phosphorylation activities of the target PTS systems were appreciably affected. The results are consistent with the suggestion that integral membrane transport proteins form an interacting network in vivo with physiological consequences, dependent on specific transporters and their concentrations in the membrane.
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Affiliation(s)
- Mohammad Aboulwafa
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, California, USA.,Department of Microbiology and Immunology, Faculty of Pharmacy, Ain Shams University, Cairo, Egypt
| | - Zhongge Zhang
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, California, USA
| | - Milton H Saier
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, California, USA,
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18
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Medrano-Soto A, Ghazi F, Hendargo KJ, Moreno-Hagelsieb G, Myers S, Saier MH. Expansion of the Transporter-Opsin-G protein-coupled receptor superfamily with five new protein families. PLoS One 2020; 15:e0231085. [PMID: 32320418 PMCID: PMC7176098 DOI: 10.1371/journal.pone.0231085] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Accepted: 03/17/2020] [Indexed: 02/06/2023] Open
Abstract
Here we provide bioinformatic evidence that the Organo-Arsenical Exporter (ArsP), Endoplasmic Reticulum Retention Receptor (KDELR), Mitochondrial Pyruvate Carrier (MPC), L-Alanine Exporter (AlaE), and the Lipid-linked Sugar Translocase (LST) protein families are members of the Transporter-Opsin-G Protein-coupled Receptor (TOG) Superfamily. These families share domains homologous to well-established TOG superfamily members, and their topologies of transmembranal segments (TMSs) are compatible with the basic 4-TMS repeat unit characteristic of this Superfamily. These repeat units tend to occur twice in proteins as a result of intragenic duplication events, often with subsequent gain/loss of TMSs in many superfamily members. Transporters within the ArsP family allow microbial pathogens to expel toxic arsenic compounds from the cell. Members of the KDELR family are involved in the selective retrieval of proteins that reside in the endoplasmic reticulum. Proteins of the MPC family are involved in the transport of pyruvate into mitochondria, providing the organelle with a major oxidative fuel. Members of family AlaE excrete L-alanine from the cell. Members of the LST family are involved in the translocation of lipid-linked glucose across the membrane. These five families substantially expand the range of substrates of transport carriers in the superfamily, although KDEL receptors have no known transport function. Clustering of protein sequences reveals the relationships among families, and the resulting tree correlates well with the degrees of sequence similarity documented between families. The analyses and programs developed to detect distant relatedness, provide insights into the structural, functional, and evolutionary relationships that exist between families of the TOG superfamily, and should be of value to many other investigators.
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Affiliation(s)
- Arturo Medrano-Soto
- Department of Molecular Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, California, United States of America
| | - Faezeh Ghazi
- Department of Molecular Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, California, United States of America
| | - Kevin J. Hendargo
- Department of Molecular Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, California, United States of America
| | | | - Scott Myers
- Department of Molecular Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, California, United States of America
| | - Milton H. Saier
- Department of Molecular Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, California, United States of America
- * E-mail:
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19
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Wang SC, Davejan P, Hendargo KJ, Javadi-Razaz I, Chou A, Yee DC, Ghazi F, Lam KJK, Conn AM, Madrigal A, Medrano-Soto A, Saier MH. Expansion of the Major Facilitator Superfamily (MFS) to include novel transporters as well as transmembrane-acting enzymes. Biochim Biophys Acta Biomembr 2020; 1862:183277. [PMID: 32205149 DOI: 10.1016/j.bbamem.2020.183277] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 03/14/2020] [Accepted: 03/17/2020] [Indexed: 12/14/2022]
Abstract
The Major Facilitator Superfamily (MFS) is currently the largest characterized superfamily of transmembrane secondary transport proteins. Its diverse members are found in essentially all organisms in the biosphere and function by uniport, symport, and/or antiport mechanisms. In 1993 we first named and described the MFS which then consisted of 5 previously known families that had not been known to be related, and by 2012 we had identified a total of 74 families, classified phylogenetically within the MFS, all of which included only transport proteins. This superfamily has since expanded to 89 families, all included under TC# 2.A.1, and a few transporter families outside of TC# 2.A.1 were identified as members of the MFS. In this study, we assign nine previously unclassified protein families in the Transporter Classification Database (TCDB; http://www.tcdb.org) to the MFS based on multiple criteria and bioinformatic methodologies. In addition, we find integral membrane domains distantly related to partial or full-length MFS permeases in Lysyl tRNA Synthases (TC# 9.B.111), Lysylphosphatidyl Glycerol Synthases (TC# 4.H.1), and cytochrome b561 transmembrane electron carriers (TC# 5.B.2). Sequence alignments, overlap of hydropathy plots, compatibility of repeat units, similarity of complexity profiles of transmembrane segments, shared protein domains and 3D structural similarities between transport proteins were analyzed to assist in inferring homology. The MFS now includes 105 families.
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Affiliation(s)
- Steven C Wang
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, CA 92093-0116, United States of America
| | - Pauldeen Davejan
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, CA 92093-0116, United States of America
| | - Kevin J Hendargo
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, CA 92093-0116, United States of America
| | - Ida Javadi-Razaz
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, CA 92093-0116, United States of America
| | - Amy Chou
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, CA 92093-0116, United States of America
| | - Daniel C Yee
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, CA 92093-0116, United States of America
| | - Faezeh Ghazi
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, CA 92093-0116, United States of America
| | - Katie Jing Kay Lam
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, CA 92093-0116, United States of America
| | - Adam M Conn
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, CA 92093-0116, United States of America
| | - Assael Madrigal
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, CA 92093-0116, United States of America
| | - Arturo Medrano-Soto
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, CA 92093-0116, United States of America
| | - Milton H Saier
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, CA 92093-0116, United States of America.
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20
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Aboulwafa M, Zhang Z, Saier MH. Protein:Protein interactions in the cytoplasmic membrane apparently influencing sugar transport and phosphorylation activities of the e. coli phosphotransferase system. PLoS One 2019; 14:e0219332. [PMID: 31751341 PMCID: PMC6872149 DOI: 10.1371/journal.pone.0219332] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Accepted: 10/13/2019] [Indexed: 01/05/2023] Open
Abstract
The multicomponent phosphoenolpyruvate (PEP)-dependent sugar-transporting phosphotransferase system (PTS) in Escherichia coli takes up sugar substrates from the medium and concomitantly phosphorylates them, releasing sugar phosphates into the cytoplasm. We have recently provided evidence that many of the integral membrane PTS permeases interact with the fructose PTS (FruA/FruB) [1]. However, the biochemical and physiological significance of this finding was not known. We have carried out molecular genetic/biochemical/physiological studies that show that interactions of the fructose PTS often enhance, but sometimes inhibit the activities of other PTS transporters many fold, depending on the target PTS system under study. Thus, the glucose (Glc), mannose (Man), mannitol (Mtl) and N-acetylglucosamine (NAG) permeases exhibit enhanced in vivo sugar transport and sometimes in vitro PEP-dependent sugar phosphorylation activities while the galactitol (Gat) and trehalose (Tre) systems show inhibited activities. This is observed when the fructose system is induced to high levels and prevented when the fruA/fruB genes are deleted. Overexpression of the fruA and/or fruB genes in the absence of fructose induction during growth also enhances the rates of uptake of other hexoses. The β-galactosidase activities of man, mtl, and gat-lacZ transcriptional fusions and the sugar-specific transphosphorylation activities of these enzyme transporters were not affected either by frustose induction or by fruAB overexpression, showing that the rates of synthesis of the target PTS permeases were not altered. We thus suggest that specific protein-protein interactions within the cytoplasmic membrane regulate transport in vivo (and sometimes the PEP-dependent phosphorylation activities in vitro) of PTS permeases in a physiologically meaningful way that may help to provide a hierarchy of preferred PTS sugars. These observations appear to be applicable in principle to other types of transport systems as well.
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Affiliation(s)
- Mohammad Aboulwafa
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, CA, United States of America
- Department of Microbiology and Immunology, Faculty of Pharmacy, Ain Shams University, Abbassia, Cairo, Egypt
| | - Zhongge Zhang
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, CA, United States of America
| | - Milton H. Saier
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, CA, United States of America
- * E-mail:
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21
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Rodionova IA, Heidari Tajabadi F, Zhang Z, Rodionov DA, Saier MH. A Riboflavin Transporter in Bdellovibrio exovorous JSS. J Mol Microbiol Biotechnol 2019; 29:27-34. [PMID: 31509826 DOI: 10.1159/000501354] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Accepted: 06/05/2019] [Indexed: 12/12/2022] Open
Abstract
The ImpX transporters of the drug/metabolite transporter superfamily were first proposed to transport riboflavin (RF; vitamin B2) based on findings of a cis-regulatory RNA element responding to flavin mononucleotide (an FMN riboswitch). Bdellovibrio exovorous JSS has a homolog belonging to this superfamily. It has 10 TMSs and shows 30% identity to the previously characterized ImpX transporter from Fusobacterium nucleatum. However, the ImpX homolog is not regulated by an FMN-riboswitch. In order to test the putative function of the ImpX homolog from B. exovorous (BexImpX), we cloned and heterologously expressed its gene. We used functional complementation, growth inhibition experiments, direct uptake experiments and inhibition studies, suggesting a high degree of specificity for RF uptake. The EC50 for growth with RF was estimated to be in the range 0.5-1 µM, estimated from the half-maximal RF concentration supporting the growth of a RF auxotrophic Escherichia coli strain, but the Khalf for RF uptake was 20 µM. Transport experiments suggested that the energy source is the proton motive force but that NaCl stimulates uptake. Thus, members of the ImpX family members are capable of RF uptake, not only in RF prototrophic species such as F. nucleatum, but also in the B2 auxotrophic species, B. exovorous.
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Affiliation(s)
- Irina A Rodionova
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, San Diego, California, USA
| | - Fereshteh Heidari Tajabadi
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, San Diego, California, USA.,Department of Plant Protection, University of Tehran, Tehran, Iran
| | - Zhongge Zhang
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, San Diego, California, USA
| | - Dmitry A Rodionov
- Sanford Burnham Prebys Medical Research Institute, San Diego, California, USA
| | - Milton H Saier
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, San Diego, California, USA,
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22
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Buyuktimkin B, Zafar H, Saier MH. Comparative genomics of the transportome of Ten Treponema species. Microb Pathog 2019; 132:87-99. [PMID: 31029716 DOI: 10.1016/j.micpath.2019.04.034] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 04/02/2019] [Accepted: 04/23/2019] [Indexed: 02/08/2023]
Abstract
Treponema is a diverse bacterial genus, the species of which can be pathogenic, symbiotic, or free living. These treponemes can cause various diseases in humans and other animals, such as periodontal disease, bovine digital dermatitis and animal skin lesions. However, the most important and well-studied disease of treponemes that affects humans is 'syphilis'. This disease is caused by Treponema pallidum subspecie pallidum with 11-12 million new cases around the globe on an annual basis. In this study we analyze the transportome of ten Treponema species, with emphasis on the types of encoded transport proteins and their substrates. Of the ten species examined, two (T. primitia and T. azonutricium) reside as symbionts in the guts of termites; six (T. pallidum, T. paraluiscuniculi, T. pedis, T. denticola, T. putidum and T. brennaborense) are pathogens of either humans or animals, and T. caldarium and T. succinifaciens are avirulent species, the former being thermophilic. All ten species have a repertoire of transport proteins that assists them in residing in their respective ecological niches. For instance, oral pathogens use transport proteins that take up nutrients uniquely present in their ecosystem; they also encode multiple multidrug/macromolecule exporters that protect against antimicrobials and aid in biofilm formation. Proteins of termite gut symbionts convert cellulose into other sugars that can be metabolized by the host. As often observed for pathogens and symbionts, several of these treponemes have reduced genome sizes, and their small genomes correlate with their dependencies on the host. Overall, the transportomes of T. pallidum and other pathogens have a conglomerate of parasitic lifestyle-assisting proteins. For example, a T. pallidum repeat protein (TprK) mediates immune evasion; outer membrane proteins (OMPs) allow nutrient uptake and end product export, and several ABC transporters catalyze sugar uptake, considered pivotal to parasitic lifestyles. Taken together, the results of this study yield new information that may help open new avenues of treponeme research.
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Affiliation(s)
- Bora Buyuktimkin
- Department of Molecular Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA, 92093-0116, USA
| | - Hassan Zafar
- Department of Molecular Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA, 92093-0116, USA; Institute of Microbiology, University of Agriculture, Faisalabad, Punjab, Pakistan
| | - Milton H Saier
- Department of Molecular Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA, 92093-0116, USA.
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Abstract
The communities of beneficial bacteria that live in our intestines, the gut microbiome, are important for the development and function of the immune system. Bacteroides species make up a significant fraction of the human gut microbiome, and can be probiotic and pathogenic, depending upon various genetic and environmental factors. These can cause disease conditions such as intra-abdominal sepsis, appendicitis, bacteremia, endocarditis, pericarditis, skin infections, brain abscesses and meningitis. In this study, we identify the transport systems and predict their substrates within seven Bacteroides species, all shown to be probiotic; however, four of them (B. thetaiotaomicron, B. vulgatus, B. ovatus, B. fragilis) can be pathogenic (probiotic and pathogenic; PAP), while B. cellulosilyticus, B. salanitronis and B. dorei are believed to play only probiotic roles (only probiotic; OP). The transport system characteristics of the four PAP and three OP strains were identified and tabulated, and results were compared among the seven strains, and with E. coli and Salmonella strains. The Bacteroides strains studied contain similarities and differences in the numbers and types of transport proteins tabulated, but both OP and PAP strains contain similar outer membrane carbohydrate receptors, pore-forming toxins and protein secretion systems, the similarities were noteworthy, but these Bacteroides strains showed striking differences with probiotic and pathogenic enteric bacteria, particularly with respect to their high affinity outer membrane receptors and auxiliary proteins involved in complex carbohydrate utilization. The results reveal striking similarities between the PAP and OP species of Bacteroides, and suggest that OP species may possess currently unrecognized pathogenic potential.
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Affiliation(s)
- Hassan Zafar
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, CA, United States of America
- Institute of Microbiology, University of Agriculture, Faisalabad, Punjab, Pakistan
| | - Milton H. Saier
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, CA, United States of America
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Rodionova IA, Goodacre N, Do J, Hosseinnia A, Babu M, Uetz P, Saier MH. The uridylyltransferase GlnD and tRNA modification GTPase MnmE allosterically control Escherichia coli folylpoly-γ-glutamate synthase FolC. J Biol Chem 2018; 293:15725-15732. [PMID: 30089654 DOI: 10.1074/jbc.ra118.004425] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Revised: 07/31/2018] [Indexed: 01/20/2023] Open
Abstract
Folate derivatives are important cofactors for enzymes in several metabolic processes. Folate-related inhibition and resistance mechanisms in bacteria are potential targets for antimicrobial therapies and therefore a significant focus of current research. Here, we report that the activity of Escherichia coli poly-γ-glutamyl tetrahydrofolate/dihydrofolate synthase (FolC) is regulated by glutamate/glutamine-sensing uridylyltransferase (GlnD), THF-dependent tRNA modification enzyme (MnmE), and UDP-glucose dehydrogenase (Ugd) as shown by direct in vitro protein-protein interactions. Using kinetics analyses, we observed that GlnD, Ugd, and MnmE activate FolC many-fold by decreasing the K half of FolC for its substrate l-glutamate. Moreover, FolC inhibited the GTPase activity of MnmE at low GTP concentrations. The growth phenotypes associated with these proteins are discussed. These results, obtained using direct in vitro enzyme assays, reveal unanticipated networks of allosteric regulatory interactions in the folate pathway in E. coli and indicate regulation of polyglutamylated tetrahydrofolate biosynthesis by the availability of nitrogen sources, signaled by the glutamine-sensing GlnD protein.
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Affiliation(s)
- Irina A Rodionova
- From the Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, California 92093-0116,
| | - Norman Goodacre
- Center for the Study of Biological Complexity, Virginia Commonwealth University, Richmond, Virginia 23284, and
| | - Jimmy Do
- From the Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, California 92093-0116
| | - Ali Hosseinnia
- Department of Biochemistry, University of Regina, Regina, Saskatchewan S4S 0A2, Canada
| | - Mohan Babu
- Department of Biochemistry, University of Regina, Regina, Saskatchewan S4S 0A2, Canada
| | - Peter Uetz
- Center for the Study of Biological Complexity, Virginia Commonwealth University, Richmond, Virginia 23284, and
| | - Milton H Saier
- From the Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, California 92093-0116,
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25
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Medrano-Soto A, Moreno-Hagelsieb G, McLaughlin D, Ye ZS, Hendargo KJ, Saier MH. Bioinformatic characterization of the Anoctamin Superfamily of Ca2+-activated ion channels and lipid scramblases. PLoS One 2018; 13:e0192851. [PMID: 29579047 PMCID: PMC5868767 DOI: 10.1371/journal.pone.0192851] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Accepted: 01/31/2018] [Indexed: 01/01/2023] Open
Abstract
Our laboratory has developed bioinformatic strategies for identifying distant phylogenetic relationships and characterizing families and superfamilies of transport proteins. Results using these tools suggest that the Anoctamin Superfamily of cation and anion channels, as well as lipid scramblases, includes three functionally characterized families: the Anoctamin (ANO), Transmembrane Channel (TMC) and Ca2+-permeable Stress-gated Cation Channel (CSC) families; as well as four families of functionally uncharacterized proteins, which we refer to as the Anoctamin-like (ANO-L), Transmembrane Channel-like (TMC-L), and CSC-like (CSC-L1 and CSC-L2) families. We have constructed protein clusters and trees showing the relative relationships among the seven families. Topological analyses suggest that the members of these families have essentially the same topologies. Comparative examination of these homologous families provides insight into possible mechanisms of action, indicates the currently recognized organismal distributions of these proteins, and suggests drug design potential for the disease-related channel proteins.
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Affiliation(s)
- Arturo Medrano-Soto
- Department of Molecular Biology, University of California at San Diego, La Jolla, California, United States of America
| | | | - Daniel McLaughlin
- Department of Molecular Biology, University of California at San Diego, La Jolla, California, United States of America
| | - Zachary S. Ye
- Department of Molecular Biology, University of California at San Diego, La Jolla, California, United States of America
| | - Kevin J. Hendargo
- Department of Molecular Biology, University of California at San Diego, La Jolla, California, United States of America
| | - Milton H. Saier
- Department of Molecular Biology, University of California at San Diego, La Jolla, California, United States of America
- * E-mail:
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Heidari Tajabadi F, Medrano-Soto A, Ahmadzadeh M, Salehi Jouzani G, Saier MH. Comparative Analyses of Transport Proteins Encoded within the Genomes of Bdellovibrio bacteriovorus HD100 and Bdellovibrio exovorus JSS. J Mol Microbiol Biotechnol 2017; 27:332-349. [PMID: 29212086 DOI: 10.1159/000484563] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Accepted: 10/17/2017] [Indexed: 12/21/2022] Open
Abstract
Bdellovibrio, δ-proteobacteria, including B. bacteriovorus (Bba) and B. exovorus (Bex), are obligate predators of other Gram-negative bacteria. While Bba grows in the periplasm of the prey cell, Bex grows externally. We have analyzed and compared the transport proteins of these 2 organisms based on the current contents of the Transporter Classification Database (TCDB; www.tcdb.org). Bba has 103 transporters more than Bex, 50% more secondary carriers, and 3 times as many MFS carriers. Bba has far more metabolite transporters than Bex as expected from its larger genome, but there are 2 times more carbohydrate uptake and drug efflux systems, and 3 times more lipid transporters. Bba also has polyamine and carboxylate transporters lacking in Bex. Bba has more than twice as many members of the Mot-Exb family of energizers, but both may have energizers for gliding motility. They use entirely different types of systems for iron acquisition. Both contain unexpectedly large numbers of pseudogenes and incomplete systems, suggesting that they are undergoing genome size reduction. Interestingly, all 5 outer-membrane receptors in Bba are lacking in Bex. The 2 organisms have similar numbers and types of peptide and amino acid uptake systems as well as protein and carbohydrate secretion systems. The differences observed correlate with and may account, in part, for the different lifestyles of these 2 bacterial predators.
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Moreno-Hagelsieb G, Vitug B, Medrano-Soto A, Saier MH. The Membrane Attack Complex/Perforin Superfamily. J Mol Microbiol Biotechnol 2017; 27:252-267. [PMID: 29145176 DOI: 10.1159/000481286] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Accepted: 09/05/2017] [Indexed: 12/30/2022] Open
Abstract
The membrane attack complex/perforin (MACPF) superfamily consists of a diverse group of proteins involved in bacterial pathogenesis and sporulation as well as eukaryotic immunity, embryonic development, neural migration and fruiting body formation. The present work shows that the evolutionary relationships between the members of the superfamily, previously suggested by comparison of their tertiary structures, can also be supported by analyses of their primary structures. The superfamily includes the MACPF family (TC 1.C.39), the cholesterol-dependent cytolysin (CDC) family (TC 1.C.12.1 and 1.C.12.2) and the pleurotolysin pore-forming (pleurotolysin B) family (TC 1.C.97.1), as revealed by expansion of each family by comparison against a large protein database, and by the comparisons of their hidden Markov models. Clustering analyses demonstrated grouping of the CDC homologues separately from the 12 MACPF subfamilies, which also grouped separately from the pleurotolysin B family. Members of the MACPF superfamily revealed a remarkably diverse range of proteins spanning eukaryotic, bacterial, and archaeal taxonomic domains, with notable variations in protein domain architectures. Our strategy should also be helpful in putting together other highly divergent protein families.
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Abstract
In this issue of Structure, McCoy et al. (2016) describe the 2.55-Å X-ray structure of the outward-facing occluded conformation of the Bacillus cereus maltose transporter MalT. This structure represents the penultimate piece needed to complete the picture of the transport cycle of the glucose superfamily of membrane-spanning EIIC components.
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Affiliation(s)
- Ake Vastermark
- Department of Molecular Biology, University of California at San Diego, La Jolla, CA 92093-0116, USA
| | - Milton H Saier
- Department of Molecular Biology, University of California at San Diego, La Jolla, CA 92093-0116, USA.
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Humayun MZ, Zhang Z, Butcher AM, Moshayedi A, Saier MH. Hopping into a hot seat: Role of DNA structural features on IS5-mediated gene activation and inactivation under stress. PLoS One 2017; 12:e0180156. [PMID: 28666002 PMCID: PMC5493358 DOI: 10.1371/journal.pone.0180156] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Accepted: 06/09/2017] [Indexed: 11/30/2022] Open
Abstract
Insertion sequence elements (IS elements) are proposed to play major roles in shaping the genetic and phenotypic landscapes of prokaryotic cells. Recent evidence has raised the possibility that environmental stress conditions increase IS hopping into new sites, and often such hopping has the phenotypic effect of relieving the stress. Although stress-induced targeted mutations have been reported for a number of E. coli genes, the glpFK (glycerol utilization) and the cryptic bglGFB (β-glucoside utilization) systems are among the best characterized where the effects of IS insertion-mediated gene activation are well-characterized at the molecular level. In the glpFK system, starvation of cells incapable of utilizing glycerol leads to an IS5 insertion event that activates the glpFK operon, and enables glycerol utilization. In the case of the cryptic bglGFB operon, insertion of IS5 (and other IS elements) into a specific region in the bglG upstream sequence has the effect of activating the operon in both growing cells, and in starving cells. However, a major unanswered question in the glpFK system, the bgl system, as well as other examples, has been why the insertion events are promoted at specific locations, and how the specific stress condition (glycerol starvation for example) can be mechanistically linked to enhanced insertion at a specific locus. In this paper, we show that a specific DNA structural feature (superhelical stress-induced duplex destabilization, SIDD) is associated with "stress-induced" IS5 insertion in the glpFK, bglGFB, flhDC, fucAO and nfsB systems. We propose a speculative mechanistic model that links specific environmental conditions to the unmasking of an insertional hotspot in the glpFK system. We demonstrate that experimentally altering the predicted stability of a SIDD element in the nfsB gene significantly impacts IS5 insertion at its hotspot.
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Affiliation(s)
- M. Zafri Humayun
- Department of Microbiology, Biochemistry & Molecular Genetics, Rutgers—New Jersey Medical School, Newark, NJ, United States of America
| | - Zhongge Zhang
- Department of Molecular Biology, Division of Biological Sciences, University of California San Diego, La Jolla, CA, United States of America
| | - Anna M. Butcher
- Department of Molecular Biology, Division of Biological Sciences, University of California San Diego, La Jolla, CA, United States of America
| | - Aref Moshayedi
- Department of Molecular Biology, Division of Biological Sciences, University of California San Diego, La Jolla, CA, United States of America
| | - Milton H. Saier
- Department of Molecular Biology, Division of Biological Sciences, University of California San Diego, La Jolla, CA, United States of America
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30
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Rodionova IA, Zhang Z, Mehla J, Goodacre N, Babu M, Emili A, Uetz P, Saier MH. The phosphocarrier protein HPr of the bacterial phosphotransferase system globally regulates energy metabolism by directly interacting with multiple enzymes in Escherichia coli. J Biol Chem 2017. [PMID: 28634232 DOI: 10.1074/jbc.m117.795294] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The histidine-phosphorylatable phosphocarrier protein (HPr) is an essential component of the sugar-transporting phosphotransferase system (PTS) in many bacteria. Recent interactome findings suggested that HPr interacts with several carbohydrate-metabolizing enzymes, but whether HPr plays a regulatory role was unclear. Here, we provide evidence that HPr interacts with a large number of proteins in Escherichia coli We demonstrate HPr-dependent allosteric regulation of the activities of pyruvate kinase (PykF, but not PykA), phosphofructokinase (PfkB, but not PfkA), glucosamine-6-phosphate deaminase (NagB), and adenylate kinase (Adk). HPr is either phosphorylated on a histidyl residue (HPr-P) or non-phosphorylated (HPr). PykF is activated only by non-phosphorylated HPr, which decreases the PykF Khalf for phosphoenolpyruvate by 10-fold (from 3.5 to 0.36 mm), thus influencing glycolysis. PfkB activation by HPr, but not by HPr-P, resulted from a decrease in the Khalf for fructose-6-P, which likely influences both gluconeogenesis and glycolysis. Moreover, NagB activation by HPr was important for the utilization of amino sugars, and allosteric inhibition of Adk activity by HPr-P, but not by HPr, allows HPr to regulate the cellular energy charge coordinately with glycolysis. These observations suggest that HPr serves as a directly interacting global regulator of carbon and energy metabolism and probably of other physiological processes in enteric bacteria.
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Affiliation(s)
- Irina A Rodionova
- From the Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, California 92093-0116
| | - Zhongge Zhang
- From the Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, California 92093-0116
| | - Jitender Mehla
- Center for the Study of Biological Complexity, Virginia Commonwealth University, Richmond, Virginia 23284
| | - Norman Goodacre
- Center for the Study of Biological Complexity, Virginia Commonwealth University, Richmond, Virginia 23284
| | - Mohan Babu
- Department of Biochemistry, Research and Innovation Centre, University of Regina, Regina, Saskatchewan S4S 0A2, Canada
| | - Andrew Emili
- Donnelly Centre, University of Toronto, Toronto, Ontario M5S 3E1, Canada
| | - Peter Uetz
- Center for the Study of Biological Complexity, Virginia Commonwealth University, Richmond, Virginia 23284
| | - Milton H Saier
- From the Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, California 92093-0116,.
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31
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Do J, Zafar H, Saier MH. Comparative genomics of transport proteins in probiotic and pathogenic Escherichia coli and Salmonella enterica strains. Microb Pathog 2017; 107:106-115. [PMID: 28344124 PMCID: PMC5591646 DOI: 10.1016/j.micpath.2017.03.022] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Revised: 12/13/2016] [Accepted: 03/21/2017] [Indexed: 12/11/2022]
Abstract
Escherichia coli is a genetically diverse species that can be pathogenic, probiotic, commensal, or a harmless laboratory strain. Pathogenic strains of E. coli cause urinary tract infections, diarrhea, hemorrhagic colitis, and pyelonephritis, while the two known probiotic E. coli strains combat inflammatory bowel disease and play a role in immunomodulation. Salmonella enterica, a close relative of E. coli, includes two important pathogenic serovars, Typhi and Typhimurium, causing typhoid fever and enterocolitis in humans, respectively, with the latter strain also causing a lethal typhoid fever-like disease in mice. In this study, we identify the transport systems and their substrates within seven E. coli strains: two probiotic strains, two extracellular pathogens, two intracellular pathogens, and K-12, as well as the two intracellular pathogenic S. enterica strains noted above. Transport systems characteristic of each probiotic or pathogenic species were thus identified, and the tabulated results obtained with all of these strains were compared. We found that the probiotic and pathogenic strains generally contain more iron-siderophore and sugar transporters than E. coli K-12. Pathogens have increased numbers of pore-forming toxins, protein secretion systems, decarboxylation-driven Na+ exporters, electron flow-driven monovalent cation exporters, and putative transporters of unknown function compared to the probiotic strains. Both pathogens and probiotic strains encode metabolite transporters that reflect their intracellular versus extracellular environments. The results indicate that the probiotic strains live extracellularly. It seems that relatively few virulence factors can convert a beneficial or commensal microorganism into a pathogen. Taken together, the results reveal the distinguishing features of these strains and provide a starting point for future engineering of beneficial enteric bacteria.
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Affiliation(s)
- Jimmy Do
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, CA 92093-0116, USA
| | - Hassan Zafar
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, CA 92093-0116, USA
| | - Milton H Saier
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, CA 92093-0116, USA.
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Lee J, Ghosh S, Saier MH. Comparative genomic analyses of transport proteins encoded within the red algae Chondrus crispus, Galdieria sulphuraria, and Cyanidioschyzon merolae 11. J Phycol 2017; 53:503-521. [PMID: 28328149 PMCID: PMC5591647 DOI: 10.1111/jpy.12534] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Accepted: 11/21/2016] [Indexed: 05/15/2023]
Abstract
Galdieria sulphuraria and Cyanidioschyzon merolae are thermo-acidophilic unicellular red algal cousins capable of living in volcanic environments, although the former can additionally thrive in the presence of toxic heavy metals. Bioinformatic analyses of transport systems were carried out on their genomes, as well as that of the mesophilic multicellular red alga Chondrus crispus (Irish moss). We identified transport proteins related to the metabolic capabilities, physiological properties, and environmental adaptations of these organisms. Of note is the vast array of transporters encoded in G. sulphuraria capable of importing a variety of carbon sources, particularly sugars and amino acids, while C. merolae and C. crispus have relatively few such proteins. Chondrus crispus may prefer short chain acids to sugars and amino acids. In addition, the number of encoded proteins pertaining to heavy metal ion transport is highest in G. sulphuraria and lowest in C. crispus. All three organisms preferentially utilize secondary carriers over primary active transporters, suggesting that their primary source of energy derives from electron flow rather than substrate-level phosphorylation. Surprisingly, the percentage of inorganic ion transporters encoded in C. merolae more closely resembles that of C. crispus than G. sulphuraria, but only C. crispus appears to signal via voltage-gated cation channels and possess a Na+ /K+ -ATPase and a Na+ exporting pyrophosphatase. The results presented in this report further our understanding of the metabolic potential and toxic compound resistances of these three organisms.
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Affiliation(s)
| | | | - Milton H. Saier
- Corresponding Author: Tel +1 858 534 4084 Fax: +1 858 534 7108 (M.H. Saier)
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33
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Saier MH, Trevors JT. Science, Innovation and the Future of Humanity. J Mol Microbiol Biotechnol 2017; 27:128-132. [PMID: 28448972 DOI: 10.1159/000467401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Affiliation(s)
- Milton H Saier
- Division of Biological Sciences, University of California at San Diego, La Jolla, CA, USA
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Zhang Z, Kukita C, Humayun MZ, Saier MH. Environment-directed activation of the Escherichia coliflhDC operon by transposons. Microbiology (Reading) 2017; 163:554-569. [PMID: 28100305 DOI: 10.1099/mic.0.000426] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The flagellar system in Escherichia coli K12 is expressed under the control of the flhDC-encoded master regulator FlhDC. Transposition of insertion sequence (IS) elements to the upstream flhDC promoter region up-regulates transcription of this operon, resulting in a more rapid motility. Wang and Wood (ISME J 2011;5:1517-1525) provided evidence that insertion of IS5 into upstream activating sites occurs at higher rates in semi-solid agar media in which swarming behaviour is allowed as compared with liquid or solid media where swarming cannot occur. We confirm this conclusion and show that three IS elements, IS1, IS3 and IS5, transpose to multiple upstream sites within a 370 bp region of the flhDC operon control region. Hot spots for IS insertion correlate with positions of stress-induced DNA duplex destabilization (SIDD). We show that IS insertion occurs at maximal rates in 0.24 % agar, with rates decreasing dramatically with increasing or decreasing agar concentrations. In mixed cultures, we show that these mutations preferentially arise from the wild-type parent at frequencies of up to 3×10-3 cell-1 day-1 when the inoculated parental and co-existing IS-activated mutant cells are entering the stationary growth phase. We rigorously show that the apparent increased mutation frequencies cannot be accounted for by increased swimming or by increased growth under the selective conditions used. Thus, our data are consistent with the possibility that appropriate environmental conditions, namely those that permit but hinder flagellar rotation, result in the activation of a mutational pathway that involves IS element insertion upstream of the flhDC operon.
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Affiliation(s)
- Zhongge Zhang
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, CA 92093-0116, USA
| | - Chika Kukita
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, CA 92093-0116, USA
| | - M Zafri Humayun
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers New Jersey Medical School, Newark, NJ 07101-1709, USA
| | - Milton H Saier
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, CA 92093-0116, USA
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35
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Vastermark A, Driker A, Weng J, Li X, Wang J, Saier MH. Difference distance map data of alternative crystal forms of UlaA. Data Brief 2016; 10:198-201. [PMID: 27995154 PMCID: PMC5154960 DOI: 10.1016/j.dib.2016.11.087] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Revised: 11/18/2016] [Accepted: 11/23/2016] [Indexed: 11/16/2022] Open
Abstract
We introduce the value of information obtained by comparing alternative crystal forms of the same sub-state (of outward open UlaA, our example protein), which is found in the same lattice configuration but different space groups. We compare instability estimates obtained using this new method (alternative crystal forms) with temperature factors. Using a transport assay result, we correlate observations for two homologous secondary structure elements, and show that the alternative states method for obtaining instability estimates provide differentiating information about an important and immobilized mid-TMS region. The data presented in this article are related to the article entitled “The V-motifs facilitate the substrate capturing step of the PTS elevator mechanism” (A. Vastermark, A. Driker, J. Weng, X. Li, J. Wang, M.H. Saier Jr., 2016).
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Affiliation(s)
- Ake Vastermark
- Department of Molecular Biology, University of California at San Diego, La Jolla, CA 92093-0116, USA
| | - Adelle Driker
- Department of Molecular Biology, University of California at San Diego, La Jolla, CA 92093-0116, USA
| | - Jingwei Weng
- Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Department of Chemistry and Institute of Biomedical Sciences, Fudan University, Shanghai, People's Republic of China
| | - Xiaochun Li
- Laboratory of Cell Biology, Howard Hughes Medical Institute, The Rockefeller University, New York, New York 10065, USA
| | - Jiawei Wang
- State Key Laboratory of Biomembrane and Membrane Biotechnology, School of Life Sciences, Tsinghua University, Beijing, People's Republic of China
| | - Milton H Saier
- Department of Molecular Biology, University of California at San Diego, La Jolla, CA 92093-0116, USA
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36
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Zhang Z, Saier MH. Transposon-mediated activation of the Escherichia coli glpFK operon is inhibited by specific DNA-binding proteins: Implications for stress-induced transposition events. Mutat Res 2016; 793-794:22-31. [PMID: 27810619 DOI: 10.1016/j.mrfmmm.2016.10.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Revised: 08/18/2016] [Accepted: 10/22/2016] [Indexed: 11/16/2022]
Abstract
Escherichia coli cells deleted for the cyclic AMP (cAMP) receptor protein (Crp) gene (Δcrp) cannot utilize glycerol because cAMP-Crp is a required activator of the glycerol utilization operon, glpFK. We have previously shown that a transposon, Insertion Sequence 5 (IS5), can insert into the upstream regulatory region of the operon to activate the glpFK promoter and enable glycerol utilization. GlpR, which represses glpFK transcription, binds to the glpFK upstream region near the site of IS5 insertion and inhibits insertion. By adding cAMP to the culture medium in ΔcyaA cells, we here show that the cAMP-Crp complex, which also binds to the glpFK upstream regulatory region, inhibits IS5 hopping into the activating site. Control experiments showed that the frequencies of mutations in response to cAMP were independent of parental cell growth rate and the selection procedure. These findings led to the prediction that glpFK-activating IS5 insertions can also occur in wild-type (Crp+) cells under conditions that limit cAMP production. Accordingly, we found that IS5 insertion into the activating site in wild-type cells is elevated in the presence of glycerol and a non-metabolizable sugar analogue that lowers cytoplasmic cAMP concentrations. The resultant IS5 insertion mutants arising in this minimal medium become dominant constituents of the population after prolonged periods of growth. The results show that DNA binding transcription factors can reversibly mask a favored transposon target site, rendering a hot spot for insertion less favored. Such mechanisms could have evolved by natural selection to overcome environmental adversity.
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Affiliation(s)
- Zhongge Zhang
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, CA 92093-0116, United States
| | - Milton H Saier
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, CA 92093-0116, United States.
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37
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Kuppusamykrishnan H, Chau LM, Moreno-Hagelsieb G, Saier MH. Analysis of 58 Families of Holins Using a Novel Program, PhyST. J Mol Microbiol Biotechnol 2016; 26:381-388. [PMID: 27553295 DOI: 10.1159/000448040] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Accepted: 06/28/2016] [Indexed: 01/21/2023] Open
Abstract
We have designed a freely accessible program, PhyST, which allows the automated characterization of any family of homologous proteins within the Transporter Classification Database. The program performs an NCBI-PSI-BLAST search and reports (1) the average protein sequence length with standard deviations, (2) the average predicted number of transmembrane segments, (3) the total number of homologues retrieved, (4) a quantitative list of all source phyla, and (5) potential fusion proteins of sizes considerably exceeding the average size of the proteins retrieved. We have applied this program to 58 families of holins, and the results are presented. The results show that holins are very rarely fused to other protein domains, suggesting that holins form transmembrane pores as homooligomers without the participation of other proteins or protein domains.
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Affiliation(s)
- Harikrishnan Kuppusamykrishnan
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, Calif., USA
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38
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Buyuktimkin B, Saier MH. Comparative analyses of transport proteins encoded within the genomes of Leptospira species. Microb Pathog 2016; 98:118-31. [PMID: 27296707 DOI: 10.1016/j.micpath.2016.06.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Accepted: 06/08/2016] [Indexed: 02/02/2023]
Abstract
Select species of the bacterial genus Leptospira are causative agents of leptospirosis, an emerging global zoonosis affecting nearly one million people worldwide annually. We examined two Leptospira pathogens, Leptospira interrogans serovar Lai str. 56601 and Leptospira borgpetersenii serovar Hardjo-bovis str. L550, as well as the free-living leptospiral saprophyte, Leptospira biflexa serovar Patoc str. 'Patoc 1 (Ames)'. The transport proteins of these leptospires were identified and compared using bioinformatics to gain an appreciation for which proteins may be related to pathogenesis and saprophytism. L. biflexa possesses a disproportionately high number of secondary carriers for metabolite uptake and environmental adaptability as well as an increased number of inorganic cation transporters providing ionic homeostasis and effective osmoregulation in a rapidly changing environment. L. interrogans and L. borgpetersenii possess far fewer transporters, but those that they all have are remarkably similar, with near-equivalent representation in most transporter families. These two Leptospira pathogens also possess intact sphingomyelinases, holins, and virulence-related outer membrane porins. These virulence-related factors, in conjunction with decreased transporter substrate versatility, indicate that pathogenicity arose in Leptospira correlating to progressively narrowing ecological niches and the emergence of a limited set of proteins responsible for host invasion. The variability of host tropism and mortality rates by infectious leptospires suggests that small differences in individual sets of proteins play important physiological and pathological roles.
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Affiliation(s)
- Bora Buyuktimkin
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, CA 92093-0116, USA
| | - Milton H Saier
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, CA 92093-0116, USA.
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39
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Reddy BL, Saier MH. Properties and Phylogeny of 76 Families of Bacterial and Eukaryotic Organellar Outer Membrane Pore-Forming Proteins. PLoS One 2016; 11:e0152733. [PMID: 27064789 PMCID: PMC4827864 DOI: 10.1371/journal.pone.0152733] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Accepted: 03/18/2016] [Indexed: 12/11/2022] Open
Abstract
We here report statistical analyses of 76 families of integral outer membrane pore-forming proteins (OMPPs) found in bacteria and eukaryotic organelles. 47 of these families fall into one superfamily (SFI) which segregate into fifteen phylogenetic clusters. Families with members of the same protein size, topology and substrate specificities often cluster together. Virtually all OMPP families include only proteins that form transmembrane pores. Nine such families, all of which cluster together in the SFI phylogenetic tree, contain both α- and β-structures, are multi domain, multi subunit systems, and transport macromolecules. Most other SFI OMPPs transport small molecules. SFII and SFV homologues derive from Actinobacteria while SFIII and SFIV proteins derive from chloroplasts. Three families of actinobacterial OMPPs and two families of eukaryotic OMPPs apparently consist primarily of α-helices (α-TMSs). Of the 71 families of (putative) β-barrel OMPPs, only twenty could not be assigned to a superfamily, and these derived primarily from Actinobacteria (1), chloroplasts (1), spirochaetes (8), and proteobacteria (10). Proteins were identified in which two or three full length OMPPs are fused together. Family characteristic are described and evidence agrees with a previous proposal suggesting that many arose by adjacent β-hairpin structural unit duplications.
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Affiliation(s)
- Bhaskara L. Reddy
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, California, United States of America
| | - Milton H. Saier
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, California, United States of America
- * E-mail:
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40
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Saier MH, Reddy VS, Tsu BV, Ahmed MS, Li C, Moreno-Hagelsieb G. The Transporter Classification Database (TCDB): recent advances. Nucleic Acids Res 2015; 44:D372-9. [PMID: 26546518 PMCID: PMC4702804 DOI: 10.1093/nar/gkv1103] [Citation(s) in RCA: 451] [Impact Index Per Article: 50.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Accepted: 10/11/2015] [Indexed: 11/16/2022] Open
Abstract
The Transporter Classification Database (TCDB; http://www.tcdb.org) is a freely accessible reference database for transport protein research, which provides structural, functional, mechanistic, evolutionary and disease/medical information about transporters from organisms of all types. TCDB is the only transport protein classification database adopted by the International Union of Biochemistry and Molecular Biology (IUBMB). It consists of more than 10 000 non-redundant transport systems with more than 11 000 reference citations, classified into over 1000 transporter families. Transporters in TCDB can be single or multi-component systems, categorized in a functional/phylogenetic hierarchical system of classes, subclasses, families, subfamilies and transport systems. TCDB also includes updated software designed to analyze the distinctive features of transport proteins, extending its usefulness. Here we present a comprehensive update of the database contents and features and summarize recent discoveries recorded in TCDB.
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Affiliation(s)
- Milton H Saier
- Department of Molecular Biology, University of California at San Diego, La Jolla, CA 92093-0116, USA
| | - Vamsee S Reddy
- Department of Molecular Biology, University of California at San Diego, La Jolla, CA 92093-0116, USA Department of Medical Sciences, Boston University School of Medicine, 72 E Concord St., Boston, MA 02118, USA
| | - Brian V Tsu
- Department of Molecular Biology, University of California at San Diego, La Jolla, CA 92093-0116, USA
| | - Muhammad Saad Ahmed
- Department of Biological Engineering, School of Life Sciences, Beijing Institute of Technology, Beijing 100081, People's Republic of China
| | - Chun Li
- Department of Biological Engineering, School of Life Sciences, Beijing Institute of Technology, Beijing 100081, People's Republic of China
| | - Gabriel Moreno-Hagelsieb
- Department of Molecular Biology, University of California at San Diego, La Jolla, CA 92093-0116, USA Department of Biology, Wilfrid Laurier University, 75 University Ave W, Waterloo, ON, Canada N2L 3C5
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41
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Zhu C, Nigam KB, Date RC, Bush KT, Springer SA, Saier MH, Wu W, Nigam SK. Evolutionary Analysis and Classification of OATs, OCTs, OCTNs, and Other SLC22 Transporters: Structure-Function Implications and Analysis of Sequence Motifs. PLoS One 2015; 10:e0140569. [PMID: 26536134 PMCID: PMC4633038 DOI: 10.1371/journal.pone.0140569] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2011] [Accepted: 09/28/2015] [Indexed: 12/11/2022] Open
Abstract
The SLC22 family includes organic anion transporters (OATs), organic cation transporters (OCTs) and organic carnitine and zwitterion transporters (OCTNs). These are often referred to as drug transporters even though they interact with many endogenous metabolites and signaling molecules (Nigam, S.K., Nature Reviews Drug Discovery, 14:29-44, 2015). Phylogenetic analysis of SLC22 supports the view that these transporters may have evolved over 450 million years ago. Many OAT members were found to appear after a major expansion of the SLC22 family in mammals, suggesting a physiological and/or toxicological role during the mammalian radiation. Putative SLC22 orthologs exist in worms, sea urchins, flies, and ciona. At least six groups of SLC22 exist. OATs and OCTs form two Major clades of SLC22, within which (apart from Oat and Oct subclades), there are also clear Oat-like, Octn, and Oct-related subclades, as well as a distantly related group we term "Oat-related" (which may have different functions). Based on available data, it is arguable whether SLC22A18, which is related to bacterial drug-proton antiporters, should be assigned to SLC22. Disease-causing mutations, single nucleotide polymorphisms (SNPs) and other functionally analyzed mutations in OAT1, OAT3, URAT1, OCT1, OCT2, OCTN1, and OCTN2 map to the first extracellular domain, the large central intracellular domain, and transmembrane domains 9 and 10. These regions are highly conserved within subclades, but not between subclades, and may be necessary for SLC22 transporter function and functional diversification. Our results not only link function to evolutionarily conserved motifs but indicate the need for a revised sub-classification of SLC22.
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Affiliation(s)
- Christopher Zhu
- Departments of Pediatrics, University of California at San Diego, La Jolla, California, United States of America
| | - Kabir B. Nigam
- Departments of Medicine, University of California at San Diego, La Jolla, California, United States of America
| | - Rishabh C. Date
- Departments of Medicine, University of California at San Diego, La Jolla, California, United States of America
| | - Kevin T. Bush
- Departments of Pediatrics, University of California at San Diego, La Jolla, California, United States of America
| | - Stevan A. Springer
- Departments of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, California, United States of America
| | - Milton H. Saier
- Departments of Molecular Biology, University of California at San Diego, La Jolla, California, United States of America
| | - Wei Wu
- Departments of Medicine, University of California at San Diego, La Jolla, California, United States of America
- * E-mail: (SKN); (WW)
| | - Sanjay K. Nigam
- Departments of Pediatrics, University of California at San Diego, La Jolla, California, United States of America
- Departments of Medicine, University of California at San Diego, La Jolla, California, United States of America
- Departments of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, California, United States of America
- * E-mail: (SKN); (WW)
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42
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Abstract
The LysE superfamily consists of transmembrane transport proteins that catalyze export of amino acids, lipids and heavy metal ions. Statistical means were used to show that it includes newly identified families including transporters specific for (1) tellurium, (2) iron/lead, (3) manganese, (4) calcium, (5) nickel/cobalt, (6) amino acids, and (7) peptidoglycolipids as well as (8) one family of transmembrane electron carriers. Internal repeats and conserved motifs were identified, and multiple alignments, phylogenetic trees and average hydropathy, amphipathicity and similarity plots provided evidence that all members of the superfamily derived from a single common 3-TMS precursor peptide via intragenic duplication. Their common origin implies that they share common structural, mechanistic and functional attributes. The transporters of this superfamily play important roles in ionic homeostasis, cell envelope assembly, and protection from excessive cytoplasmic heavy metal/metabolite concentrations. They thus influence the physiology and pathogenesis of numerous microbes, being potential targets of drug action.
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Affiliation(s)
- Brian V. Tsu
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, California, United States of America
| | - Milton H. Saier
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, California, United States of America
- * E-mail:
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43
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Buyuktimkin B, Saier MH. Comparative genomic analyses of transport proteins encoded within the genomes of Leptospira species. Microb Pathog 2015; 88:52-64. [PMID: 26247102 DOI: 10.1016/j.micpath.2015.07.019] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Revised: 07/21/2015] [Accepted: 07/23/2015] [Indexed: 11/17/2022]
Abstract
Select species of the bacterial genus Leptospira are causative agents of leptospirosis, an emerging global zoonosis affecting nearly one million people worldwide annually. We examined two Leptospira pathogens, Leptospira interrogans serovar Lai str. 56601 and Leptospira borgpetersenii serovar Hardjo-bovis str. L550, as well as the free-living leptospiral saprophyte, Leptospira biflexa serovar Patoc str. 'Patoc 1 (Ames)'. The transport proteins of these leptospires were identified and compared using bioinformatics to gain an appreciation for which proteins may be related to pathogenesis and saprophytism. L. biflexa possesses a disproportionately high number of secondary carriers for metabolite uptake and environmental adaptability as well as an increased number of inorganic cation transporters providing ionic homeostasis and effective osmoregulation in a rapidly changing environment. L. interrogans and L. borgpetersenii possess far fewer transporters, but those that they have are remarkably similar, with near-equivalent representation in most transporter families. These two Leptospira pathogens also possess intact sphingomyelinases, holins, and virulence-related outer membrane porins. These virulence-related factors, in conjunction with decreased transporter substrate versatility, indicate that pathogenicity was accompanied by progressively narrowing ecological niches and the emergence of a limited set of proteins responsible for host invasion. The variability of host tropism and mortality rates by infectious leptospires suggests that small differences in individual sets of proteins play important physiological and pathological roles.
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Affiliation(s)
- Bora Buyuktimkin
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, CA 92093-0116, USA
| | - Milton H Saier
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, CA 92093-0116, USA.
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44
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Babbitt PC, Bagos PG, Bairoch A, Bateman A, Chatonnet A, Chen MJ, Craik DJ, Finn RD, Gloriam D, Haft DH, Henrissat B, Holliday GL, Isberg V, Kaas Q, Landsman D, Lenfant N, Manning G, Nagano N, Srinivasan N, O'Donovan C, Pruitt KD, Sowdhamini R, Rawlings ND, Saier MH, Sharman JL, Spedding M, Tsirigos KD, Vastermark A, Vriend G. Creating a specialist protein resource network: a meeting report for the protein bioinformatics and community resources retreat. Database (Oxford) 2015; 2015:bav063. [PMID: 26284514 PMCID: PMC4499208 DOI: 10.1093/database/bav063] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Revised: 05/14/2015] [Accepted: 05/18/2015] [Indexed: 11/14/2022]
Abstract
During 11–12 August 2014, a Protein Bioinformatics and Community Resources Retreat was held at the Wellcome Trust Genome Campus in Hinxton, UK. This meeting brought together the principal investigators of several specialized protein resources (such as CAZy, TCDB and MEROPS) as well as those from protein databases from the large Bioinformatics centres (including UniProt and RefSeq). The retreat was divided into five sessions: (1) key challenges, (2) the databases represented, (3) best practices for maintenance and curation, (4) information flow to and from large data centers and (5) communication and funding. An important outcome of this meeting was the creation of a Specialist Protein Resource Network that we believe will improve coordination of the activities of its member resources. We invite further protein database resources to join the network and continue the dialogue.
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Affiliation(s)
- Patricia C Babbitt
- Department of Bioengineering and Therapeutic Sciences and California Institute for Quantitative Biosciences, University of California San Francisco, 1700 4th Street, San Francisco, CA 94158, USA
| | - Pantelis G Bagos
- Department of Computer Science and Biomedical Informatics, University of Thessaly, Papasiopoulou 2-4, Lamia, 35100, Greece
| | - Amos Bairoch
- SIB-Swiss Institute of Bioinformatics, CMU, 1 rue Michel Servet, 1211 Geneva 4, Switzerland
| | - Alex Bateman
- European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SD, UK
| | - Arnaud Chatonnet
- INRA, UMR866 Dynamique Musculaire et Métabolisme, F-34000 Montpellier, France
| | - Mark Jinan Chen
- Razavi Newman Center for Bioinformatics, Salk Institute, 10010 North Torrey Pines Rd., La Jolla, CA 92037, USA, ; Bioinformatics & Computational Biology, Genentech, 1 DNA Way, South San Francisco, CA 94080, USA
| | - David J Craik
- Queensland Bioscience Precinct, 306 Carmody Rd, Building 80, The University of Queensland, Australia
| | - Robert D Finn
- European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SD, UK
| | - David Gloriam
- Department of Drug Design and Pharmacology, University of Copenhagen, Jagtvej 162, 2100 København Ø, Denmark
| | - Daniel H Haft
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Building 38 A, 8600 Rockville Pike, Bethesda, MD 20894, USA
| | - Bernard Henrissat
- Architecture et Fonction des Macromolécules Biologiques, CNRS, Aix-Marseille Université, 13288 Marseille, France, ; Department of Biological Sciences, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Gemma L Holliday
- Department of Bioengineering and Therapeutic Sciences and California Institute for Quantitative Biosciences, University of California San Francisco, 1700 4th Street, San Francisco, CA 94158, USA
| | - Vignir Isberg
- Department of Drug Design and Pharmacology, University of Copenhagen, Jagtvej 162, 2100 København Ø, Denmark, ; CMBI, Raboudumc, Geert Grootplein Zuid 26-28, 6525 GA Nijmegen, The Netherlands
| | - Quentin Kaas
- Queensland Bioscience Precinct, 306 Carmody Rd, Building 80, The University of Queensland, Australia
| | - David Landsman
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Building 38 A, 8600 Rockville Pike, Bethesda, MD 20894, USA
| | - Nicolas Lenfant
- INRA, UMR866 Dynamique Musculaire et Métabolisme, F-34000 Montpellier, France
| | - Gerard Manning
- Razavi Newman Center for Bioinformatics, Salk Institute, 10010 North Torrey Pines Rd., La Jolla, CA 92037, USA, ; Bioinformatics & Computational Biology, Genentech, 1 DNA Way, South San Francisco, CA 94080, USA
| | - Nozomi Nagano
- Biotechnology Research Institute for Drug Discovery, National Institute of Advanced Industrial Science and Technology (AIST), 2-4-7 Aomi, Koto-ku, Tokyo 135-0064, Japan
| | | | - Claire O'Donovan
- European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SD, UK
| | - Kim D Pruitt
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Building 38 A, 8600 Rockville Pike, Bethesda, MD 20894, USA
| | - Ramanathan Sowdhamini
- National Centre for Biological Sciences, TIFR, GKVK Campus, Bangalore 560 065, India
| | - Neil D Rawlings
- European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SD, UK
| | - Milton H Saier
- Department of Molecular Biology, University of California at San Diego, La Jolla, CA 92093-0116, USA
| | - Joanna L Sharman
- Centre for Integrative Physiology, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK
| | - Michael Spedding
- Spedding Research Solutions, 6 Rue Ampere, 78110 Le Vesinet, France and
| | - Konstantinos D Tsirigos
- Department of Biochemistry and Biophysics, Science for Life Laboratory, Swedish E-Science Research Center, Stockholm University, Box 1031, 17121 Solna, Sweden
| | - Ake Vastermark
- Department of Molecular Biology, University of California at San Diego, La Jolla, CA 92093-0116, USA
| | - Gerrit Vriend
- CMBI, Raboudumc, Geert Grootplein Zuid 26-28, 6525 GA Nijmegen, The Netherlands
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45
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Abstract
In 1964, Kundig, Ghosh and Roseman reported the discovery of the phosphoenolpyruvate:sugar phosphotransferase system (PTS), which they subsequently proposed might catalyze sugar transport as well as sugar phosphorylation. What we have learned in the 50 years since its discovery is that, in addition to these primary functions, the PTS serves as a complex protein kinase system that regulates a wide variety of transport, metabolic and mutagenic processes as well as the expression of numerous genes. Recent operon- and genome-sequencing projects have revealed novel PTS protein-encoding genes, many of which have yet to be functionally defined. The current picture of the PTS is that of a complex system with ramifications in all aspects of cellular physiology. Moreover, its mosaic evolutionary history is unusual and intriguing. The PTS can be considered to serve many prokaryotes in capacities of communication and coordination, as do the nervous systems of animals.
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Affiliation(s)
- Milton H Saier
- Department of Molecular Biology, University of California at San Diego, La Jolla, Calif., USA
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46
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Saier MH, Zhang Z. Control of Transposon-Mediated Directed Mutation by the Escherichia coli Phosphoenolpyruvate:Sugar Phosphotransferase System. J Mol Microbiol Biotechnol 2015; 25:226-33. [PMID: 26159081 DOI: 10.1159/000375375] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The phosphoenolpyruvate:sugar phosphotransferase system (PTS) has been shown to control transport, cell metabolism and gene expression. We here present results supporting the novel suggestion that in certain instances it also regulates the mutation rate. Directed mutations are defined as mutations that occur at higher frequencies when beneficial than when neutral or detrimental. To date, the occurrence of directed point mutations has not been documented and confirmed, but a few examples of transposon-mediated directed mutations have been reported. Here we focus on the first and best-studied example of directed mutation, which involves the regulation of insertion sequence-5 hopping into a specific site upstream of the glpFK glycerol utilization operon in Escherichia coli. This insertional event specifically activates expression of the glpFK operon, allowing the growth of wild-type cells with glycerol as a carbon source in the presence of nonmetabolizable glucose analogues which normally block glycerol utilization. The sugar-transporting PTS controls this process by regulating levels of cytoplasmic glycerol-3-phosphate and cyclic (c)AMP as established in previous publications. Direct involvement of the glycerol repressor, GlpR, and the cAMP receptor protein, Crp, in the regulation of transposon-mediated directed mutation has been demonstrated.
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Affiliation(s)
- Milton H Saier
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, Calif., USA
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47
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Abstract
Microbial products, released into the bloodstreams of mammals including humans, cross the blood-brain barrier and influence neurodevelopment. They can either promote or alleviate neurological disorders including autism spectrum disorders (ASD). This editorial describes how our microbiota influence our feelings, attitudes and mental states with particular reference to ASD.
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Affiliation(s)
- Bhaskara Lakshmi Reddy
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, Calif., USA
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48
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Västermark Å, Driker A, Li J, Saier MH. Conserved movement of TMS11 between occluded conformations of LacY and XylE of the major facilitator superfamily suggests a similar hinge-like mechanism. Proteins 2015; 83:735-45. [PMID: 25586173 DOI: 10.1002/prot.24755] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Revised: 12/17/2014] [Accepted: 12/31/2014] [Indexed: 12/11/2022]
Abstract
The Δ-distance maps can detect local remodeling that is difficult to accurately determine using superimpositions. Transmembrane segments (TMSs) 11 in both LacY and XylE of the major facilitator superfamily uniquely contribute the greatest amount of mobile surface area in the outward-occluded state and undergo analogous movements. The intracellular part of TMS11 moves away from the C-terminal domain and into the substrate cavity during the conformational change from the outward-occluded to the inward-occluded state. A difference was noted between LacY and XylE when they assumed the inward open state after releasing a substrate to the inside in which TMS11 of LacY moved further into the substrate release space, whereas in XylE, TMS11 slightly retracted into the C-terminal domain. Independent movement of the N-terminal half of TMS11 suggests that it is flexible in the middle. Repeat-swapped homology modeling was used to discover that a loop connecting TMSs 10 and 11 in LacY probably moves during the transition between the unavailable outward-open state and the outward-occluded state. TMSs 11 and the other elements displaying a notable domain-independent movement colocalize with the interdomain linker, suggesting that these elements could drive the alternating access movement between the domain halves. Preliminary evidence indicates that analogous movements occur in other members of the major facilitator superfamily.
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Affiliation(s)
- Åke Västermark
- Department of Molecular Biology, University of California at San Diego, La Jolla, California, 92093-0116
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Chiang Z, Vastermark A, Punta M, Coggill PC, Mistry J, Finn RD, Saier MH. The complexity, challenges and benefits of comparing two transporter classification systems in TCDB and Pfam. Brief Bioinform 2015; 16:865-72. [PMID: 25614388 PMCID: PMC4570203 DOI: 10.1093/bib/bbu053] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Indexed: 01/04/2023] Open
Abstract
Transport systems comprise roughly 10% of all proteins in a cell, playing critical roles in many processes. Improving and expanding their classification is an important goal that can affect studies ranging from comparative genomics to potential drug target searches. It is not surprising that different classification systems for transport proteins have arisen, be it within a specialized database, focused on this functional class of proteins, or as part of a broader classification system for all proteins. Two such databases are the Transporter Classification Database (TCDB) and the Protein family (Pfam) database. As part of a long-term endeavor to improve consistency between the two classification systems, we have compared transporter annotations in the two databases to understand the rationale for differences and to improve both systems. Differences sometimes reflect the fact that one database has a particular transporter family while the other does not. Differing family definitions and hierarchical organizations were reconciled, resulting in recognition of 69 Pfam ‘Domains of Unknown Function’, which proved to be transport protein families to be renamed using TCDB annotations. Of over 400 potential new Pfam families identified from TCDB, 10% have already been added to Pfam, and TCDB has created 60 new entries based on Pfam data. This work, for the first time, reveals the benefits of comprehensive database comparisons and explains the differences between Pfam and TCDB.
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Kumar U, Saier MH. Comparative Genomic Analysis of Integral Membrane Transport Proteins in Ciliates. J Eukaryot Microbiol 2014; 62:167-87. [DOI: 10.1111/jeu.12156] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Revised: 04/23/2014] [Accepted: 04/28/2014] [Indexed: 11/25/2022]
Affiliation(s)
- Ujjwal Kumar
- Division of Biological Sciences; University of California at San Diego; La Jolla California
| | - Milton H. Saier
- Division of Biological Sciences; University of California at San Diego; La Jolla California
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