1
|
Castro VS, Conte CA, de Souza Figueiredo EE, Yang X, Stanford K. Efficacy of Quaternary Ammonium Compounds for Control of Individual and Mixed Cultures of Escherichia coli with High- and Low-Quaternary Ammonium Compounds Resistance. Foodborne Pathog Dis 2023; 20:261-269. [PMID: 37379475 DOI: 10.1089/fpd.2023.0005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/30/2023] Open
Abstract
Escherichia coli is a well-characterized micro-organism in scientific literature. Similarly, quaternary ammonium compounds (QACs) are historical sanitizers in food processing. However, the use of QACs has been questioned due to bacterial resistance in some studies. Therefore, this study aimed to compare effects of single and mixed cultures of E. coli strains of different serogroups with either high (six strains) or low (five strains) resistance to QACs. Twenty-five combinations of strains with either high (H)- or low (L)-QAC resistance were analyzed (H + H vs. L + L). After exposure to QAC, combinations with statistical differences (p < 0.05) compared with individuals were selected and an inactivation model determined using GInaFit®. Only one combination of two strains (C23 and C20) with low-QAC resistance (mixture T18) had greater resistance (p < 0.05) than the individual isolates. The combination T18 and individual strain C23 presented a Weibull model, whereas the other isolated strain (C20) presented a biphasic inactivation model with a shoulder. Whole genome sequencing determined that unlike C20, C23 carried yehW, which may have led to Weibull inactivation. Possibly, very rapid interaction of C20 with the QAC favored increased survival of C23 and overall persistence of the T18 mixture. Consequently, our results indicate that individual E. coli with low-QAC resistance can synergistically interfere with QAC inactivation.
Collapse
Affiliation(s)
- Vinicius Silva Castro
- Department of Biochemistry, Institute of Chemistry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
- Department of Biological Sciences, University of Lethbridge, Lethbridge, Alberta, Canada
| | - Carlos Adam Conte
- Department of Biochemistry, Institute of Chemistry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | | | - Xianqin Yang
- Science and Technology Branch, Agriculture and AgriFood Canada, Lacombe, Alberta, Canada
| | - Kim Stanford
- Department of Biological Sciences, University of Lethbridge, Lethbridge, Alberta, Canada
| |
Collapse
|
2
|
Holden ER, Yasir M, Turner AK, Wain J, Charles IG, Webber MA. Genome-wide analysis of genes involved in efflux function and regulation within Escherichia coli and Salmonella enterica serovar Typhimurium. MICROBIOLOGY (READING, ENGLAND) 2023; 169. [PMID: 36745554 DOI: 10.1099/mic.0.001296] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The incidence of multidrug-resistant bacteria is increasing globally, with efflux pumps being a fundamental platform limiting drug access and synergizing with other mechanisms of resistance. Increased expression of efflux pumps is a key feature of most cells that are resistant to multiple antibiotics. Whilst expression of efflux genes can confer benefits, production of complex efflux systems is energetically costly and the expression of efflux is highly regulated, with cells balancing benefits against costs. This study used TraDIS-Xpress, a genome-wide transposon mutagenesis technology, to identify genes in Escherichia coli and Salmonella Typhimurium involved in drug efflux and its regulation. We exposed mutant libraries to the canonical efflux substrate acriflavine in the presence and absence of the efflux inhibitor phenylalanine-arginine β-naphthylamide. Comparisons between conditions identified efflux-specific and drug-specific responses. Known efflux-associated genes were easily identified, including acrAB, tolC, marRA, ramRA and soxRS, confirming the specificity of the response. Further genes encoding cell envelope maintenance enzymes and products involved with stringent response activation, DNA housekeeping, respiration and glutathione biosynthesis were also identified as affecting efflux activity in both species. This demonstrates the deep relationship between efflux regulation and other cellular regulatory networks. We identified a conserved set of pathways crucial for efflux activity in these experimental conditions, which expands the list of genes known to impact on efflux efficacy. Responses in both species were similar and we propose that these common results represent a core set of genes likely to be relevant to efflux control across the Enterobacteriaceae.
Collapse
Affiliation(s)
- Emma R Holden
- Quadram Institute Bioscience, Norwich Research Park, Norwich, Norfolk, NR4 7UQ, UK
| | - Muhammad Yasir
- Quadram Institute Bioscience, Norwich Research Park, Norwich, Norfolk, NR4 7UQ, UK
| | - A Keith Turner
- Quadram Institute Bioscience, Norwich Research Park, Norwich, Norfolk, NR4 7UQ, UK
| | - John Wain
- Quadram Institute Bioscience, Norwich Research Park, Norwich, Norfolk, NR4 7UQ, UK.,Norwich Medical School, University of East Anglia, Norwich Research Park, Norwich, Norfolk, NR4 7TJ, UK
| | - Ian G Charles
- Quadram Institute Bioscience, Norwich Research Park, Norwich, Norfolk, NR4 7UQ, UK.,Norwich Medical School, University of East Anglia, Norwich Research Park, Norwich, Norfolk, NR4 7TJ, UK
| | - Mark A Webber
- Quadram Institute Bioscience, Norwich Research Park, Norwich, Norfolk, NR4 7UQ, UK.,Norwich Medical School, University of East Anglia, Norwich Research Park, Norwich, Norfolk, NR4 7TJ, UK
| |
Collapse
|
3
|
Genome Analysis of Halomonas elongata Strain 153B and Insights Into Polyhydroxyalkanoate Synthesis and Adaptive Mechanisms to High Saline Environments. Curr Microbiol 2022; 80:18. [PMID: 36460760 DOI: 10.1007/s00284-022-03115-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 11/07/2022] [Indexed: 12/03/2022]
Abstract
Species of the Halomonas genus are gram-negative, aerobic, moderately halophilic bacteria that synthesize polyhydroxyalkanoates (PHAs) and other high-value products that have a wide range of potential uses in the food, feed, cosmetics, pharmaceutical, and chemical sectors. Genome sequencing studies allow for the description and comparison of genetic traits with other strains and species, allowing for the exploration of the organism's potential, necessary to further biotechnology applications. Here, the genome of Halomonas elongata strain 153B was sequenced, its features compared to 5 other strains and 7 species, and a description of features for adaptations to hypersaline environments and bioproducts synthesis was done. Whole-genome analysis showed H. elongata 153B has more similar features to the reference strain H. elongata DSM 2581 compared to 4 other reported strains. Comparative genomics showed 2064 core genomic clusters between the strains and 666 singletons for strain 153B. Several genes in transport and signaling, osmoregulation, and oxidative stress that have roles in adaptation to environments with high osmolarity were also revealed. These appear to form an intricate network of overlapping systems carefully coordinated to bring about adaptation. H. elongata 153B genes for the synthesis of PHAs, ectoine, vitamins, and the degradation of drugs and aromatic compounds were described. The results will aid in the study of halophile physiology, provide a mine for valuable enzymes, and help speed up research for other biotechnology applications.
Collapse
|
4
|
Dumitrescu DG, Gordon EM, Kovalyova Y, Seminara AB, Duncan-Lowey B, Forster ER, Zhou W, Booth CJ, Shen A, Kranzusch PJ, Hatzios SK. A microbial transporter of the dietary antioxidant ergothioneine. Cell 2022; 185:4526-4540.e18. [PMID: 36347253 PMCID: PMC9691600 DOI: 10.1016/j.cell.2022.10.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 08/16/2022] [Accepted: 10/07/2022] [Indexed: 11/09/2022]
Abstract
Low-molecular-weight (LMW) thiols are small-molecule antioxidants required for the maintenance of intracellular redox homeostasis. However, many host-associated microbes, including the gastric pathogen Helicobacter pylori, unexpectedly lack LMW-thiol biosynthetic pathways. Using reactivity-guided metabolomics, we identified the unusual LMW thiol ergothioneine (EGT) in H. pylori. Dietary EGT accumulates to millimolar levels in human tissues and has been broadly implicated in mitigating disease risk. Although certain microorganisms synthesize EGT, we discovered that H. pylori acquires this LMW thiol from the host environment using a highly selective ATP-binding cassette transporter-EgtUV. EgtUV confers a competitive colonization advantage in vivo and is widely conserved in gastrointestinal microbes. Furthermore, we found that human fecal bacteria metabolize EGT, which may contribute to production of the disease-associated metabolite trimethylamine N-oxide. Collectively, our findings illustrate a previously unappreciated mechanism of microbial redox regulation in the gut and suggest that inter-kingdom competition for dietary EGT may broadly impact human health.
Collapse
Affiliation(s)
- Daniel G Dumitrescu
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT 06520, USA; Department of Chemistry, Yale University, New Haven, CT 06520, USA; Microbial Sciences Institute, Yale University, West Haven, CT 06516, USA
| | - Elizabeth M Gordon
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT 06520, USA; Microbial Sciences Institute, Yale University, West Haven, CT 06516, USA
| | - Yekaterina Kovalyova
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT 06520, USA; Department of Chemistry, Yale University, New Haven, CT 06520, USA; Microbial Sciences Institute, Yale University, West Haven, CT 06516, USA
| | - Anna B Seminara
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT 06520, USA; Microbial Sciences Institute, Yale University, West Haven, CT 06516, USA; Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Brianna Duncan-Lowey
- Department of Microbiology, Harvard Medical School, Boston, MA 02115, USA; Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, MA 02115, USA
| | - Emily R Forster
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA 02111, USA; Graduate Program in Molecular Microbiology, Graduate School of Biomedical Sciences, Tufts University, Boston, MA 02111, USA
| | - Wen Zhou
- Department of Immunology and Microbiology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
| | - Carmen J Booth
- Department of Comparative Medicine, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Aimee Shen
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA 02111, USA
| | - Philip J Kranzusch
- Department of Microbiology, Harvard Medical School, Boston, MA 02115, USA; Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, MA 02115, USA; Parker Institute for Cancer Immunotherapy at Dana-Farber Cancer Institute, Boston, MA 02115, USA
| | - Stavroula K Hatzios
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT 06520, USA; Department of Chemistry, Yale University, New Haven, CT 06520, USA; Microbial Sciences Institute, Yale University, West Haven, CT 06516, USA.
| |
Collapse
|
5
|
Cui S, Zhou W, Tang X, Zhang Q, Yang B, Zhao J, Mao B, Zhang H. The Effect of Proline on the Freeze-Drying Survival Rate of Bifidobacterium longum CCFM 1029 and Its Inherent Mechanism. Int J Mol Sci 2022; 23:13500. [PMID: 36362285 PMCID: PMC9653706 DOI: 10.3390/ijms232113500] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 10/31/2022] [Accepted: 10/31/2022] [Indexed: 08/13/2024] Open
Abstract
Amino acids, which are important compatible solutes, play a significant role in probiotic lyophilization. However, studies on the functions of Bifidobacterium during freeze-drying are limited. Therefore, in this study, we compared the freeze-drying survival rate of Bifidobacterium longum CCFM 1029 cultivated in different media containing different kinds of compatible solutes. We found that the addition of 21 g/L proline to the culture media substantially improved the freeze-drying survival rate of B. longum CCFM 1029 from 18.61 ± 0.42% to 38.74 ± 1.58%. Interestingly, this change has only been observed when the osmotic pressure of the external culture environment is increased. Under these conditions, we found that proline accumulation in this strain increased significantly. This change also helped the strain to maintain its membrane integrity and the activity of some key enzymes during freeze-drying. Overall, these results show that the addition of proline can help the strain resist a tough environment during lyophilization. The findings of this study provide preliminary data for producers of probiotics who wish to achieve higher freeze-drying survival rates during industrial production.
Collapse
Affiliation(s)
- Shumao Cui
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China
- School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Wenrui Zhou
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China
- School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Xin Tang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China
- School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Qiuxiang Zhang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China
- School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Bo Yang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China
- School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Jianxin Zhao
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China
- School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Bingyong Mao
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China
- School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Hao Zhang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China
- School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
- National Engineering Research Center for Functional Food, Jiangnan University, Wuxi 214122, China
| |
Collapse
|
6
|
What do we know about osmoadaptation of Yersinia pestis? Arch Microbiol 2021; 204:11. [PMID: 34878588 DOI: 10.1007/s00203-021-02610-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 11/23/2021] [Accepted: 11/24/2021] [Indexed: 10/19/2022]
Abstract
The plague agent Yersinia pestis mainly spreads among mammalian hosts and their associated fleas. Production of a successful mammal-flea-mammal life cycle implies that Y. pestis senses and responds to distinct cues in both host and vector. Among these cues, osmolarity is a fundamental parameter. The plague bacillus lives in a tightly regulated environment in the mammalian host, while osmolarity fluctuates in the flea gut (300-550 mOsM). Here, we review the mechanisms that enable Y. pestis to perceive fluctuations in osmolarity, as well as genomic plasticity and physiological adaptation of the bacterium to this stress.
Collapse
|
7
|
van den Noort M, de Boer M, Poolman B. Stability of Ligand-induced Protein Conformation Influences Affinity in Maltose-binding Protein. J Mol Biol 2021; 433:167036. [PMID: 33957147 DOI: 10.1016/j.jmb.2021.167036] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 04/13/2021] [Accepted: 04/27/2021] [Indexed: 11/18/2022]
Abstract
Our understanding of what determines ligand affinity of proteins is poor, even with high-resolution structures available. Both the non-covalent ligand-protein interactions and the relative free energies of available conformations contribute to the affinity of a protein for a ligand. Distant, non-binding site residues can influence the ligand affinity by altering the free energy difference between a ligand-free and ligand-bound conformation. Our hypothesis is that when different ligands induce distinct ligand-bound conformations, it should be possible to tweak their affinities by changing the free energies of the available conformations. We tested this idea for the maltose-binding protein (MBP) from Escherichia coli. We used single-molecule Förster resonance energy transfer (smFRET) to distinguish several unique ligand-bound conformations of MBP. We engineered mutations, distant from the binding site, to affect the stabilities of different ligand-bound conformations. We show that ligand affinity can indeed be altered in a conformation-dependent manner. Our studies provide a framework for the tuning of ligand affinity, apart from modifying binding site residues.
Collapse
Affiliation(s)
- Marco van den Noort
- Department of Biochemistry, Groningen Biomolecular Science and Biotechnology Institute, University of Groningen, Nijenborgh 4, Groningen 9747 AG, the Netherlands
| | - Marijn de Boer
- Department of Biochemistry, Groningen Biomolecular Science and Biotechnology Institute, University of Groningen, Nijenborgh 4, Groningen 9747 AG, the Netherlands
| | - Bert Poolman
- Department of Biochemistry, Groningen Biomolecular Science and Biotechnology Institute, University of Groningen, Nijenborgh 4, Groningen 9747 AG, the Netherlands.
| |
Collapse
|
8
|
Imhoff JF, Rahn T, Künzel S, Keller A, Neulinger SC. Osmotic Adaptation and Compatible Solute Biosynthesis of Phototrophic Bacteria as Revealed from Genome Analyses. Microorganisms 2020; 9:E46. [PMID: 33375353 PMCID: PMC7824335 DOI: 10.3390/microorganisms9010046] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 12/21/2020] [Accepted: 12/23/2020] [Indexed: 11/21/2022] Open
Abstract
Osmotic adaptation and accumulation of compatible solutes is a key process for life at high osmotic pressure and elevated salt concentrations. Most important solutes that can protect cell structures and metabolic processes at high salt concentrations are glycine betaine and ectoine. The genome analysis of more than 130 phototrophic bacteria shows that biosynthesis of glycine betaine is common among marine and halophilic phototrophic Proteobacteria and their chemotrophic relatives, as well as in representatives of Pirellulaceae and Actinobacteria, but are also found in halophilic Cyanobacteria and Chloroherpeton thalassium. This ability correlates well with the successful toleration of extreme salt concentrations. Freshwater bacteria in general lack the possibilities to synthesize and often also to take up these compounds. The biosynthesis of ectoine is found in the phylogenetic lines of phototrophic Alpha- and Gammaproteobacteria, most prominent in the Halorhodospira species and a number of Rhodobacteraceae. It is also common among Streptomycetes and Bacilli. The phylogeny of glycine-sarcosine methyltransferase (GMT) and diaminobutyrate-pyruvate aminotransferase (EctB) sequences correlate well with otherwise established phylogenetic groups. Most significantly, GMT sequences of cyanobacteria form two major phylogenetic branches and the branch of Halorhodospira species is distinct from all other Ectothiorhodospiraceae. A variety of transport systems for osmolytes are present in the studied bacteria.
Collapse
Affiliation(s)
| | - Tanja Rahn
- GEOMAR Helmholtz Centre for Ocean Research, 24105 Kiel, Germany;
| | - Sven Künzel
- Max Planck Institute for Evolutionary Biology, 24306 Plön, Germany;
| | - Alexander Keller
- Center for Computational and Theoretical Biology, University Würzburg, 97074 Würzburg, Germany;
| | | |
Collapse
|
9
|
Hu X, Li D, Qiao Y, Song Q, Guan Z, Qiu K, Cao J, Huang L. Salt tolerance mechanism of a hydrocarbon-degrading strain: Salt tolerance mediated by accumulated betaine in cells. JOURNAL OF HAZARDOUS MATERIALS 2020; 392:122326. [PMID: 32092654 DOI: 10.1016/j.jhazmat.2020.122326] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 02/15/2020] [Accepted: 02/15/2020] [Indexed: 06/10/2023]
Abstract
Rhodococcus sp. HX-2 could degrade diesel oil in the presence of 1%-10 % NaCl. The compatible solute betaine accumulated in cells with increasing NaCl concentration, and this was found to be the main mechanism of resistance of HX-2 to high salt concentration. Exogenously added betaine can be transported into cells, which improved cell growth and the percentage degradation of diesel oil in the presence of high [NaCl] in solution and in soil. Scanning electron microscopy data suggested that addition of exogenous betaine facilitated salt tolerance by stimulating exopolysaccharide production. Fourier-transform infrared analysis suggested that surface hydroxyl, amide and phosphate groups may be related to tolerance of high-salt environments. Four betaine transporter-encoding genes (H0, H1, H3, H5) and the betaine producer gene betB were induced in Rhodococcus sp. HX-2 by NaCl stress. The maximal induction of H0, H1, H3 and H5 transcription depended on high salinity plus the presence of betaine. These results demonstrate that salt tolerance is mediated by accumulated betaine in Rhodococcus sp. HX-2 cells, and the potential of this strain for application in bioremediation of hydrocarbon pollution in saline environments.
Collapse
Affiliation(s)
- Xin Hu
- College of Chemistry and Chemical Engineering, Tianjin Key Laboratory of Organic Solar Cells and Photochemical Conversion, Tianjin Key Laboratory of Drug Targeting and Bioimaging, Tianjin University of Technology, Tianjin, 300384, China
| | - Dahui Li
- College of Chemistry and Chemical Engineering, Tianjin Key Laboratory of Organic Solar Cells and Photochemical Conversion, Tianjin Key Laboratory of Drug Targeting and Bioimaging, Tianjin University of Technology, Tianjin, 300384, China
| | - Yue Qiao
- College of Chemistry and Chemical Engineering, Tianjin Key Laboratory of Organic Solar Cells and Photochemical Conversion, Tianjin Key Laboratory of Drug Targeting and Bioimaging, Tianjin University of Technology, Tianjin, 300384, China
| | - Qianqian Song
- College of Chemistry and Chemical Engineering, Tianjin Key Laboratory of Organic Solar Cells and Photochemical Conversion, Tianjin Key Laboratory of Drug Targeting and Bioimaging, Tianjin University of Technology, Tianjin, 300384, China
| | - Zhiguo Guan
- College of Chemistry and Chemical Engineering, Tianjin Key Laboratory of Organic Solar Cells and Photochemical Conversion, Tianjin Key Laboratory of Drug Targeting and Bioimaging, Tianjin University of Technology, Tianjin, 300384, China
| | - Kaixuan Qiu
- College of Chemistry and Chemical Engineering, Tianjin Key Laboratory of Organic Solar Cells and Photochemical Conversion, Tianjin Key Laboratory of Drug Targeting and Bioimaging, Tianjin University of Technology, Tianjin, 300384, China
| | - Jiachang Cao
- College of Chemistry and Chemical Engineering, Tianjin Key Laboratory of Organic Solar Cells and Photochemical Conversion, Tianjin Key Laboratory of Drug Targeting and Bioimaging, Tianjin University of Technology, Tianjin, 300384, China
| | - Lei Huang
- College of Chemistry and Chemical Engineering, Tianjin Key Laboratory of Organic Solar Cells and Photochemical Conversion, Tianjin Key Laboratory of Drug Targeting and Bioimaging, Tianjin University of Technology, Tianjin, 300384, China.
| |
Collapse
|
10
|
Jindal S, Yang L, Day PJ, Kell DB. Involvement of multiple influx and efflux transporters in the accumulation of cationic fluorescent dyes by Escherichia coli. BMC Microbiol 2019; 19:195. [PMID: 31438868 PMCID: PMC6704527 DOI: 10.1186/s12866-019-1561-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Accepted: 07/31/2019] [Indexed: 12/11/2022] Open
Abstract
Background It is widely believed that most xenobiotics cross biomembranes by diffusing through the phospholipid bilayer, and that the use of protein transporters is an occasional adjunct. According to an alternative view, phospholipid bilayer transport is negligible, and several different transporters may be involved in the uptake of an individual molecular type. We recognise here that the availability of gene knockout collections allows one to assess the contributions of all potential transporters, and flow cytometry based on fluorescence provides a convenient high-throughput assay for xenobiotic uptake in individual cells. Results We used high-throughput flow cytometry to assess the ability of individual gene knockout strains of E coli to take up two membrane-permeable, cationic fluorescent dyes, namely the carbocyanine diS-C3(5) and the DNA dye SYBR Green. Individual strains showed a large range of distributions of uptake. The range of modal steady-state uptakes for the carbocyanine between the different strains was 36-fold. Knockouts of the ATP synthase α- and β-subunits greatly inhibited uptake, implying that most uptake was ATP-driven rather than being driven by a membrane potential. Dozens of transporters changed the steady-state uptake of the dye by more than 50% with respect to that of the wild type, in either direction (increased or decreased); knockouts of known influx and efflux transporters behaved as expected, giving credence to the general strategy. Many of the knockouts with the most reduced uptake were transporter genes of unknown function (‘y-genes’). Similarly, several overexpression variants in the ‘ASKA’ collection had the anticipated, opposite effects. Similar results were obtained with SYBR Green (the range being approximately 69-fold). Although it too contains a benzothiazole motif there was negligible correlation between its uptake and that of the carbocyanine when compared across the various strains (although the membrane potential is presumably the same in each case). Conclusions Overall, we conclude that the uptake of these dyes may be catalysed by a great many transporters of putatively broad and presently unknown specificity, and that the very large range between the ‘lowest’ and the ‘highest’ levels of uptake, even in knockouts of just single genes, implies strongly that phospholipid bilayer transport is indeed negligible. This work also casts serious doubt upon the use of such dyes as quantitative stains for representing either bioenergetic parameters or the amount of cellular DNA in unfixed cells (in vivo). By contrast, it opens up their potential use as transporter assay substrates in high-throughput screening. Electronic supplementary material The online version of this article (10.1186/s12866-019-1561-0) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Srijan Jindal
- Department of Chemistry, The University of Manchester, 131 Princess St, Manchester, M1 7DN, UK.,Manchester Institute of Biotechnology, The University of Manchester, 131 Princess St, Manchester, M1 7DN, UK.,Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, M13 9PT, UK
| | - Lei Yang
- Novo Nordisk Foundation Centre for Biosustainability, Technical University of Denmark, Building 220, Kemitorvet, 2800 Kgs, Lyngby, Denmark
| | - Philip J Day
- Manchester Institute of Biotechnology, The University of Manchester, 131 Princess St, Manchester, M1 7DN, UK.,Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, M13 9PT, UK
| | - Douglas B Kell
- Department of Chemistry, The University of Manchester, 131 Princess St, Manchester, M1 7DN, UK. .,Manchester Institute of Biotechnology, The University of Manchester, 131 Princess St, Manchester, M1 7DN, UK. .,Novo Nordisk Foundation Centre for Biosustainability, Technical University of Denmark, Building 220, Kemitorvet, 2800 Kgs, Lyngby, Denmark. .,Department of Biochemistry, Institute of Integrative Biology, Faculty of Health and Life Sciences, University of Liverpool, Crown St, Liverpool, L69 7ZB, UK.
| |
Collapse
|
11
|
Ronzheimer S, Warmbold B, Arnhold C, Bremer E. The GbsR Family of Transcriptional Regulators: Functional Characterization of the OpuAR Repressor. Front Microbiol 2018; 9:2536. [PMID: 30405586 PMCID: PMC6207618 DOI: 10.3389/fmicb.2018.02536] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2018] [Accepted: 10/04/2018] [Indexed: 11/13/2022] Open
Abstract
Accumulation of compatible solutes is a common stress response of microorganisms challenged by high osmolarity; it can be achieved either through synthesis or import. These processes have been intensively studied in Bacillus subtilis, where systems for the production of the compatible solutes proline and glycine betaine have been identified, and in which five transporters for osmostress protectants (Opu) have been characterized. Glycine betaine synthesis relies on the import of choline via the substrate-restricted OpuB system and the promiscuous OpuC transporter and its subsequent oxidation by the GbsAB enzymes. Transcription of the opuB and gbsAB operons is under control of the MarR-type regulator GbsR, which acts as an intracellular choline-responsive repressor. Modeling studies using the X-ray structure of the Mj223 protein from Methanocaldococcus jannaschii as the template suggest that GbsR is a homo-dimer with an N-terminal DNA-reading head and C-terminal dimerization domain; a flexible linker connects these two domains. In the vicinity of the linker region, an aromatic cage is predicted as the inducer-binding site, whose envisioned architecture resembles that present in choline and glycine betaine substrate-binding proteins of ABC transporters. We used bioinformatics to assess the phylogenomics of GbsR-type proteins and found that they are widely distributed among Bacteria and Archaea. Alignments of GbsR proteins and analysis of the genetic context of the corresponding structural genes allowed their assignment into four sub-groups. In one of these sub-groups of GbsR-type proteins, gbsR-type genes are associated either with OpuA-, OpuB-, or OpuC-type osmostress protectants uptake systems. We focus here on GbsR-type proteins, named OpuAR by us, that control the expression of opuA-type gene clusters. Using such a system from the marine bacterium Bacillus infantis, we show that OpuAR acts as a repressor of opuA transcription, where several compatible solutes (e.g., choline, glycine betaine, proline betaine) serve as its inducers. Site-directed mutagenesis studies allowed a rational improvement of the putative inducer-binding site in OpuAR with respect to the affinity of choline and glycine betaine binding. Collectively, our data characterize GbsR-/OpuAR-type proteins as an extended sub-group within the MarR-superfamily of transcriptional regulators and identify a novel type of substrate-inducible import system for osmostress protectants.
Collapse
Affiliation(s)
- Stefanie Ronzheimer
- Laboratory for Microbiology, Department of Biology, Philipps-Universität Marburg, Marburg, Germany
| | - Bianca Warmbold
- Laboratory for Microbiology, Department of Biology, Philipps-Universität Marburg, Marburg, Germany
| | - Christian Arnhold
- Laboratory for Microbiology, Department of Biology, Philipps-Universität Marburg, Marburg, Germany
| | - Erhard Bremer
- Laboratory for Microbiology, Department of Biology, Philipps-Universität Marburg, Marburg, Germany.,LOEWE Center for Synthetic Microbiology, Philipps-Universität Marburg, Marburg, Germany
| |
Collapse
|
12
|
OpuF, a New Bacillus Compatible Solute ABC Transporter with a Substrate-Binding Protein Fused to the Transmembrane Domain. Appl Environ Microbiol 2018; 84:AEM.01728-18. [PMID: 30097444 DOI: 10.1128/aem.01728-18] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2018] [Accepted: 08/08/2018] [Indexed: 01/20/2023] Open
Abstract
The accumulation of compatible solutes is a common defense of bacteria against the detrimental effects of high osmolarity. Uptake systems for these compounds are cornerstones in cellular osmostress responses because they allow the energy-preserving scavenging of osmostress protectants from environmental sources. Bacillus subtilis is well studied with respect to the import of compatible solutes and its five transport systems (OpuA, OpuB, OpuC, OpuD, and OpuE), for these stress protectants have previously been comprehensively studied. Building on this knowledge and taking advantage of the unabated appearance of new genome sequences of members of the genus Bacillus, we report here the discovery, physiological characterization, and phylogenomics of a new member of the Opu family of transporters, OpuF (OpuFA-OpuFB). OpuF is not present in B. subtilis but it is widely distributed in members of the large genus Bacillus OpuF is a representative of a subgroup of ATP-binding cassette (ABC) transporters in which the substrate-binding protein (SBP) is fused to the transmembrane domain (TMD). We studied the salient features of the OpuF transporters from Bacillus infantis and Bacillus panaciterrae by functional reconstitution in a B. subtilis chassis strain lacking known Opu transporters. A common property of the examined OpuF systems is their substrate profile; OpuF mediates the import of glycine betaine, proline betaine, homobetaine, and the marine osmolyte dimethylsulfoniopropionate (DMSP). An in silico model of the SBP domain of the TMD-SBP hybrid protein OpuFB was established. It revealed the presence of an aromatic cage, a structural feature commonly present in ligand-binding sites of compatible solute importers.IMPORTANCE The high-affinity import of compatible solutes from environmental sources is an important aspect of the cellular defense of many bacteria and archaea against the harmful effects of high external osmolarity. The accumulation of these osmostress protectants counteracts high-osmolarity-instigated water efflux, a drop in turgor to nonphysiological values, and an undue increase in molecular crowding of the cytoplasm; they thereby foster microbial growth under osmotically unfavorable conditions. Importers for compatible solutes allow the energy-preserving scavenging of osmoprotective and physiologically compliant organic solutes from environmental sources. We report here the discovery, exemplary physiological characterization, and phylogenomics of a new compatible solute importer, OpuF, widely found in members of the Bacillus genus. The OpuF system is a representative of a growing subgroup of ABC transporters in which the substrate-scavenging function of the substrate-binding protein (SBP) and the membrane-embedded substrate translocating subunit (TMD) are fused into a single polypeptide chain.
Collapse
|
13
|
Salvador M, Argandoña M, Naranjo E, Piubeli F, Nieto JJ, Csonka LN, Vargas C. Quantitative RNA-seq Analysis Unveils Osmotic and Thermal Adaptation Mechanisms Relevant for Ectoine Production in Chromohalobacter salexigens. Front Microbiol 2018; 9:1845. [PMID: 30158907 PMCID: PMC6104435 DOI: 10.3389/fmicb.2018.01845] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 07/24/2018] [Indexed: 01/18/2023] Open
Abstract
Quantitative RNA sequencing (RNA-seq) and the complementary phenotypic assays were implemented to investigate the transcriptional responses of Chromohalobacter salexigens to osmotic and heat stress. These conditions trigger the synthesis of ectoine and hydroxyectoine, two compatible solutes of biotechnological interest. Our findings revealed that both stresses make a significant impact on C. salexigens global physiology. Apart from compatible solute metabolism, the most relevant adaptation mechanisms were related to “oxidative- and protein-folding- stress responses,” “modulation of respiratory chain and related components,” and “ion homeostasis.” A general salt-dependent induction of genes related to the metabolism of ectoines, as well as repression of ectoine degradation genes by temperature, was observed. Different oxidative stress response mechanisms, secondary or primary, were induced at low and high salinity, respectively, and repressed by temperature. A higher sensitivity to H2O2 was observed at high salinity, regardless of temperature. Low salinity induced genes involved in “protein-folding-stress response,” suggesting disturbance of protein homeostasis. Transcriptional shift of genes encoding three types of respiratory NADH dehydrogenases, ATP synthase, quinone pool, Na+/H+ antiporters, and sodium-solute symporters, was observed depending on salinity and temperature, suggesting modulation of the components of the respiratory chain and additional systems involved in the generation of H+ and/or Na+ gradients. Remarkably, the Na+ intracellular content remained constant regardless of salinity and temperature. Disturbance of Na+- and H+-gradients with specific ionophores suggested that both gradients influence ectoine production, but with differences depending on the solute, salinity, and temperature conditions. Flagellum genes were strongly induced by salinity, and further induced by temperature. However, salt-induced cell motility was reduced at high temperature, possibly caused by an alteration of Na+ permeability by temperature, as dependence of motility on Na+-gradient was observed. The transcriptional induction of genes related to the synthesis and transport of siderophores correlated with a higher siderophore production and intracellular iron content only at low salinity. An excess of iron increased hydroxyectoine accumulation by 20% at high salinity. Conversely, it reduced the intracellular content of ectoines by 50% at high salinity plus high temperature. These findings support the relevance of iron homeostasis for osmoadaptation, thermoadaptation and accumulation of ectoines, in C. salexigens.
Collapse
Affiliation(s)
- Manuel Salvador
- Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Seville, Seville, Spain.,Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
| | - Montserrat Argandoña
- Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Seville, Seville, Spain
| | - Emilia Naranjo
- Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Seville, Seville, Spain
| | - Francine Piubeli
- Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Seville, Seville, Spain
| | - Joaquín J Nieto
- Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Seville, Seville, Spain
| | - Lazslo N Csonka
- Department of Biological Sciences, Purdue University, West Lafayette, IN, United States
| | - Carmen Vargas
- Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Seville, Seville, Spain
| |
Collapse
|
14
|
Zhao JH, Chen JH, Wang Y, Wang ZP, He YX. The putative compatible solute-binding protein ProX from Mycobacterium tuberculosis H37Rv: biochemical characterization and crystallographic data. ACTA CRYSTALLOGRAPHICA SECTION F-STRUCTURAL BIOLOGY COMMUNICATIONS 2018; 74:231-235. [PMID: 29633971 PMCID: PMC5894108 DOI: 10.1107/s2053230x18003771] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/05/2017] [Accepted: 03/04/2018] [Indexed: 12/12/2022]
Abstract
The putative compatible solute-binding protein ProX from Mycobacterium tuberculosis was found to bind polyphenols instead of betaine, choline or carnitine. X-ray diffraction data were collected to 2.10 Å resolution. In Mycobacterium tuberculosis, the proX gene encodes a putative compatible solute-binding protein (MtProX). However, it was found through sequence alignment that the MtProX protein has very different ligand-binding residues compared with other compatible solute-binding proteins, implying that MtProX may bind to ligands that are as yet uncharacterized. In this work, it was demonstrated that MtProX binds to polyphenols such as phloretin, monoacetylphloroglucinol and 2,4-dihydroxyacetophloroglucinol with dissociation constants between 20 and 70 µM. Crystals of MtProX were obtained using a precipitant consisting of 0.2 M NaCl, 0.1 M Tris pH 8.5, 25%(w/v) polyethylene glycol 3350. The crystals diffracted to 2.10 Å resolution and belonged to space group P43212, with unit-cell parameters a = b = 90.17, c = 161.92 Å, α = β = γ = 90.0°. Assuming the presence of two MtProX molecules in the asymmetric unit, the Matthews coefficient was calculated to be 2.74 Å3 Da−1, which corresponds to a solvent content of 55%.
Collapse
Affiliation(s)
- Jian Hong Zhao
- Institute of Urology, Lanzhou University Second Hospital, Key Laboratory of Gansu Province for Urological Diseases, Clinical Center of Gansu Province for Nephrourology, Lanzhou 730000, People's Republic of China
| | - Jiang Huai Chen
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, People's Republic of China
| | - Yong Wang
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, People's Republic of China
| | - Zhi Ping Wang
- Institute of Urology, Lanzhou University Second Hospital, Key Laboratory of Gansu Province for Urological Diseases, Clinical Center of Gansu Province for Nephrourology, Lanzhou 730000, People's Republic of China
| | - Yong Xing He
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, People's Republic of China
| |
Collapse
|
15
|
Olsson BE, Korsakova ES, Anan'ina LN, Pyankova AA, Mavrodi OV, Plotnikova EG, Mavrodi DV. Draft genome sequences of strains Salinicola socius SMB35 T, Salinicola sp. MH3R3-1 and Chromohalobacter sp. SMB17 from the Verkhnekamsk potash mining region of Russia. Stand Genomic Sci 2017; 12:39. [PMID: 28729898 PMCID: PMC5518125 DOI: 10.1186/s40793-017-0251-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Accepted: 07/12/2017] [Indexed: 09/03/2023] Open
Abstract
Halomonads are moderately halophilic bacteria that are studied as models of prokaryotic osmoadaptation and sources of enzymes and chemicals for biotechnological applications. Despite the progress in understanding the diversity of these organisms, our ability to explain ecological, metabolic, and biochemical traits of halomonads at the genomic sequence level remains limited. This study addresses this gap by presenting draft genomes of Salinicola socius SMB35T, Salinicola sp. MH3R3–1 and Chromohalobacter sp. SMB17, which were isolated from potash mine tailings in the Verkhnekamsk salt deposit area of Russia. The analysis of these genomes confirmed the importance of ectoines and quaternary amines to the capacity of halomonads to tolerate osmotic stress and adapt to hypersaline environments. The study also revealed that Chromohalobacter and Salinicola share 75–90% of the predicted proteome, but also harbor a set of genus-specific genes, which in Salinicola amounted to approximately 0.5 Mbp. These genus-specific genome segments may contribute to the phenotypic diversity of the Halomonadaceae and the ability of these organisms to adapt to changing environmental conditions and colonize new ecological niches.
Collapse
Affiliation(s)
- Björn E Olsson
- University of Skövde, School of Bioscience, Skövde, Sweden
| | - Ekaterina S Korsakova
- Institute of Ecology and Genetics of Microorganisms, Ural Branch of the Russian Academy of Sciences, Perm, Russia
| | - Lyudmila N Anan'ina
- Institute of Ecology and Genetics of Microorganisms, Ural Branch of the Russian Academy of Sciences, Perm, Russia
| | - Anna A Pyankova
- Institute of Ecology and Genetics of Microorganisms, Ural Branch of the Russian Academy of Sciences, Perm, Russia
| | - Olga V Mavrodi
- Department of Biological Sciences, The University of Southern Mississippi, Hattiesburg, MS 39406 USA
| | - Elena G Plotnikova
- Institute of Ecology and Genetics of Microorganisms, Ural Branch of the Russian Academy of Sciences, Perm, Russia
| | - Dmitri V Mavrodi
- Department of Biological Sciences, The University of Southern Mississippi, Hattiesburg, MS 39406 USA
| |
Collapse
|
16
|
Conserved ABC Transport System Regulated by the General Stress Response Pathways of Alpha- and Gammaproteobacteria. J Bacteriol 2017; 199:JB.00746-16. [PMID: 27994018 DOI: 10.1128/jb.00746-16] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Accepted: 12/13/2016] [Indexed: 01/24/2023] Open
Abstract
Brucella abortus σE1 is an EcfG family sigma factor that regulates the transcription of dozens of genes in response to diverse stress conditions and is required for maintenance of chronic infection in a mouse model. A putative ATP-binding cassette transporter operon, bab1_0223-bab1_0226, is among the most highly activated gene sets in the σE1 regulon. The proteins encoded by the operon resemble quaternary ammonium-compatible solute importers but are most similar in sequence to the broadly conserved YehZYXW system, which remains largely uncharacterized. Transcription of yehZYXW is activated by the general stress sigma factor σS in Enterobacteriaceae, which suggests a functional role for this transport system in bacterial stress response across the classes Alphaproteobacteria and Gammaproteobacteria We present evidence that B. abortus YehZYXW does not function as an importer of known compatible solutes under physiological conditions and does not contribute to the virulence defect of a σE1-null strain. The sole in vitro phenotype associated with genetic disruption of this putative transport system is reduced growth in the presence of high Li+ ion concentrations. A crystal structure of B. abortus YehZ revealed a class II periplasmic binding protein fold with significant structural homology to Archaeoglobus fulgidus ProX, which binds glycine betaine. However, the structure of the YehZ ligand-binding pocket is incompatible with high-affinity binding to glycine betaine. This is consistent with weak measured binding of YehZ to glycine betaine and related compatible solutes. We conclude that YehZYXW is a conserved, stress-regulated transport system that is phylogenetically and functionally distinct from quaternary ammonium-compatible solute importers.IMPORTANCEBrucella abortus σE1 regulates transcription in response to stressors encountered in its mammalian host and is necessary for maintenance of chronic infection in a mouse model. The functions of the majority of genes regulated by σE1 remain undefined. We present a functional/structural analysis of a conserved putative membrane transport system (YehZYXW) whose expression is strongly activated by σE1 Though annotated as a quaternary ammonium osmolyte uptake system, experimental physiological studies and measured ligand-binding properties of the periplasmic binding protein (PBP), YehZ, are inconsistent with this function. A crystal structure of B. abortus YehZ provides molecular insight into differences between bona fide quaternary ammonium osmolyte importers and YehZ-related proteins, which form a distinct phylogenetic and functional group of PBPs.
Collapse
|
17
|
Crystal Structure of the Substrate-Binding Domain from Listeria monocytogenes Bile-Resistance Determinant BilE. CRYSTALS 2016. [DOI: 10.3390/cryst6120162] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
18
|
Keseler IM, Mackie A, Santos-Zavaleta A, Billington R, Bonavides-Martínez C, Caspi R, Fulcher C, Gama-Castro S, Kothari A, Krummenacker M, Latendresse M, Muñiz-Rascado L, Ong Q, Paley S, Peralta-Gil M, Subhraveti P, Velázquez-Ramírez DA, Weaver D, Collado-Vides J, Paulsen I, Karp PD. The EcoCyc database: reflecting new knowledge about Escherichia coli K-12. Nucleic Acids Res 2016; 45:D543-D550. [PMID: 27899573 PMCID: PMC5210515 DOI: 10.1093/nar/gkw1003] [Citation(s) in RCA: 377] [Impact Index Per Article: 47.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Accepted: 11/07/2016] [Indexed: 12/16/2022] Open
Abstract
EcoCyc (EcoCyc.org) is a freely accessible, comprehensive database that collects and summarizes experimental data for Escherichia coli K-12, the best-studied bacterial model organism. New experimental discoveries about gene products, their function and regulation, new metabolic pathways, enzymes and cofactors are regularly added to EcoCyc. New SmartTable tools allow users to browse collections of related EcoCyc content. SmartTables can also serve as repositories for user- or curator-generated lists. EcoCyc now supports running and modifying E. coli metabolic models directly on the EcoCyc website.
Collapse
Affiliation(s)
- Ingrid M Keseler
- SRI International, 333 Ravenswood Ave., Menlo Park, CA 94025, USA
| | - Amanda Mackie
- Department of Chemistry and Biomolecular Sciences, Macquarie University, Sydney, NSW, Australia
| | - Alberto Santos-Zavaleta
- Programa de Genómica Computacional, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, A.P. 565-A, Cuernavaca, Morelos 62100, Mexico
| | | | - César Bonavides-Martínez
- Programa de Genómica Computacional, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, A.P. 565-A, Cuernavaca, Morelos 62100, Mexico
| | - Ron Caspi
- SRI International, 333 Ravenswood Ave., Menlo Park, CA 94025, USA
| | - Carol Fulcher
- SRI International, 333 Ravenswood Ave., Menlo Park, CA 94025, USA
| | - Socorro Gama-Castro
- Programa de Genómica Computacional, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, A.P. 565-A, Cuernavaca, Morelos 62100, Mexico
| | - Anamika Kothari
- SRI International, 333 Ravenswood Ave., Menlo Park, CA 94025, USA
| | | | | | - Luis Muñiz-Rascado
- Programa de Genómica Computacional, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, A.P. 565-A, Cuernavaca, Morelos 62100, Mexico
| | - Quang Ong
- SRI International, 333 Ravenswood Ave., Menlo Park, CA 94025, USA
| | - Suzanne Paley
- SRI International, 333 Ravenswood Ave., Menlo Park, CA 94025, USA
| | - Martin Peralta-Gil
- Programa de Genómica Computacional, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, A.P. 565-A, Cuernavaca, Morelos 62100, Mexico
| | | | - David A Velázquez-Ramírez
- Programa de Genómica Computacional, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, A.P. 565-A, Cuernavaca, Morelos 62100, Mexico
| | - Daniel Weaver
- SRI International, 333 Ravenswood Ave., Menlo Park, CA 94025, USA
| | - Julio Collado-Vides
- Programa de Genómica Computacional, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, A.P. 565-A, Cuernavaca, Morelos 62100, Mexico
| | - Ian Paulsen
- Department of Chemistry and Biomolecular Sciences, Macquarie University, Sydney, NSW, Australia
| | - Peter D Karp
- SRI International, 333 Ravenswood Ave., Menlo Park, CA 94025, USA
| |
Collapse
|