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Hagedoorn PL, Pabst M, Hanefeld U. The metal cofactor: stationary or mobile? Appl Microbiol Biotechnol 2024; 108:391. [PMID: 38910188 PMCID: PMC11194214 DOI: 10.1007/s00253-024-13206-2] [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] [Received: 03/11/2024] [Revised: 05/22/2024] [Accepted: 05/27/2024] [Indexed: 06/25/2024]
Abstract
Metal cofactors are essential for catalysis and enable countless conversions in nature. Interestingly, the metal cofactor is not always static but mobile with movements of more than 4 Å. These movements of the metal can have different functions. In the case of the xylose isomerase and medium-chain dehydrogenases, it clearly serves a catalytic purpose. The metal cofactor moves during substrate activation and even during the catalytic turnover. On the other hand, in class II aldolases, the enzymes display resting states and active states depending on the movement of the catalytic metal cofactor. This movement is caused by substrate docking, causing the metal cofactor to take the position essential for catalysis. As these metal movements are found in structurally and mechanistically unrelated enzymes, it has to be expected that this metal movement is more common than currently perceived. KEY POINTS: • Metal ions are essential cofactors that can move during catalysis. • In class II aldolases, the metal cofactors can reside in a resting state and an active state. • In MDR, the movement of the metal cofactor is essential for substrate docking.
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Affiliation(s)
- Peter-Leon Hagedoorn
- Afdeling Biotechnologie, Technische Universiteit Delft, Van der Maasweg 9, Delft, 2629 HZ, The Netherlands
| | - Martin Pabst
- Afdeling Biotechnologie, Technische Universiteit Delft, Van der Maasweg 9, Delft, 2629 HZ, The Netherlands
| | - Ulf Hanefeld
- Afdeling Biotechnologie, Technische Universiteit Delft, Van der Maasweg 9, Delft, 2629 HZ, The Netherlands.
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2
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Mannen K, Nagata T, Rozenberg A, Konno M, Del Carmen Marín M, Bagherzadeh R, Béjà O, Uchihashi T, Inoue K. Multiple Roles of a Conserved Glutamate Residue for Unique Biophysical Properties in a New Group of Microbial Rhodopsins Homologous to TAT Rhodopsin. J Mol Biol 2024; 436:168331. [PMID: 37898385 DOI: 10.1016/j.jmb.2023.168331] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Revised: 10/02/2023] [Accepted: 10/21/2023] [Indexed: 10/30/2023]
Abstract
TAT rhodopsin, a microbial rhodopsin found in the marine SAR11 bacterium HIMB114, uniquely possesses a Thr-Ala-Thr (TAT) motif in the third transmembrane helix. Because of a low pKa value of the retinal Schiff base (RSB), TAT rhodopsin exhibits both a visible light-absorbing state with the protonated RSB and a UV-absorbing state with the deprotonated RSB at a neutral pH. The UV-absorbing state, in contrast to the visible light-absorbing one, converts to a long-lived photointermediate upon light absorption, implying that TAT rhodopsin functions as a pH-dependent light sensor. Despite detailed biophysical characterization and mechanistic studies on the TAT rhodopsin, it has been unknown whether other proteins with similarly unusual features exist. Here, we identified several new rhodopsin genes homologous to the TAT rhodopsin of HIMB114 (TATHIMB) from metagenomic data. Based on the absorption spectra of expressed proteins from these genes with visible and UV peaks similar to that of TATHIMB, they were classified as Twin-peaked Rhodopsin (TwR) family. TwR genes form a gene cluster with a set of 13 ORFs conserved in subclade IIIa of SAR11 bacteria. A glutamic acid in the second transmembrane helix, Glu54, is conserved in all of the TwRs. We investigated E54Q mutants of two TwRs and revealed that Glu54 plays critical roles in regulating the RSB pKa, oligomer formation, and the efficient photoreaction of the UV-absorbing state. The discovery of novel TwRs enables us to study the universality and individuality of the characteristics revealed so far in the original TATHIMB and contributes to further studies on mechanisms of unique properties of TwRs.
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Affiliation(s)
- Kentaro Mannen
- The Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - Takashi Nagata
- The Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - Andrey Rozenberg
- Faculty of Biology, Technion - Israel Institute of Technology, Haifa 3200003, Israel
| | - Masae Konno
- The Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - María Del Carmen Marín
- The Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - Reza Bagherzadeh
- The Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | - Oded Béjà
- Faculty of Biology, Technion - Israel Institute of Technology, Haifa 3200003, Israel
| | - Takayuki Uchihashi
- Department of Physics, Nagoya University, Nagoya 464-8602, Japan; Exploratory Research Center on Life and Living Systems, National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan; Institute for Glyco-core Research, Nagoya University, Nagoya 464-8602, Japan
| | - Keiichi Inoue
- The Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan.
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3
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Lee GH, Kim JH, Ha HJ, Park HH. Structure of YdjH from Acinetobacter baumannii revealed an active site of YdjH family sugar kinase. Biochem Biophys Res Commun 2023; 664:27-34. [PMID: 37130458 DOI: 10.1016/j.bbrc.2023.04.073] [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: 04/17/2023] [Revised: 04/18/2023] [Accepted: 04/21/2023] [Indexed: 05/04/2023]
Abstract
Bacterial sugar kinase is a central enzyme for proper sugar degradation in bacteria, essential for survival and growth. Therefore, this enzyme family is a primary target for antibacterial drug development, with YdjH most preferring to phosphorylate higher-order monosaccharides with a carboxylate terminus. Sugar kinases express diverse specificity and functions, making specificity determination of this family a prominent issue. This study examines the YdjH crystal structure from Acinetobacter baumannii (abYdjH), which has an exceptionally high antibiotic resistance and is considered a superbug. Our structural and biochemical study revealed that abYdjH has a widely open lid domain and is a solution dimer. In addition, the putative active site of abYdjH was determined based on structural analysis, sequence comparison, and in silico docking. Finally, we proposed the active site-forming residues that determine various sugar specificities from abYdjH. This study contributes towards a deeper understanding of the phosphorylation process and bacterial sugar metabolism of YdjH family to design the next-generation antibiotics for targeting A. baumannii.
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Affiliation(s)
- Gwan Hee Lee
- College of Pharmacy, Chung-Ang University, Seoul, 06974, Republic of Korea; Department of Global Innovative Drugs, Graduate School of Chung-Ang University, Seoul, 06974, Republic of Korea
| | - Ju Hyeong Kim
- College of Pharmacy, Chung-Ang University, Seoul, 06974, Republic of Korea; Department of Global Innovative Drugs, Graduate School of Chung-Ang University, Seoul, 06974, Republic of Korea
| | - Hyun Ji Ha
- College of Pharmacy, Chung-Ang University, Seoul, 06974, Republic of Korea
| | - Hyun Ho Park
- College of Pharmacy, Chung-Ang University, Seoul, 06974, Republic of Korea; Department of Global Innovative Drugs, Graduate School of Chung-Ang University, Seoul, 06974, Republic of Korea.
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Karanth S, Pradhan AK. Development of a novel machine learning-based weighted modeling approach to incorporate Salmonella enterica heterogeneity on a genetic scale in a dose-response modeling framework. RISK ANALYSIS : AN OFFICIAL PUBLICATION OF THE SOCIETY FOR RISK ANALYSIS 2023; 43:440-450. [PMID: 35413139 DOI: 10.1111/risa.13924] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Estimating microbial dose-response is an important aspect of a food safety risk assessment. In recent years, there has been considerable interest to advance these models with potential incorporation of gene expression data. The aim of this study was to develop a novel machine learning model that considers the weights of expression of Salmonella genes that could be associated with illness, given exposure, in hosts. Here, an elastic net-based weighted Poisson regression method was proposed to identify Salmonella enterica genes that could be significantly associated with the illness response, irrespective of serovar. The best-fit elastic net model was obtained by 10-fold cross-validation. The best-fit elastic net model identified 33 gene expression-dose interaction terms that added to the predictability of the model. Of these, nine genes associated with Salmonella metabolism and virulence were found to be significant by the best-fit Poisson regression model (p < 0.05). This method could improve or redefine dose-response relationships for illness from relative proportions of significant genes from a microbial genetic dataset, which would help in refining endpoint and risk estimations.
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Affiliation(s)
- Shraddha Karanth
- Department of Nutrition and Food Science, University of Maryland, College Park, Maryland, USA
| | - Abani K Pradhan
- Department of Nutrition and Food Science, University of Maryland, College Park, Maryland, USA
- Center for Food Safety and Security Systems, University of Maryland, College Park, Maryland, USA
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5
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Fang Y, Stanford K, Yang X. Lactic Acid Resistance and Population Structure of Escherichia coli from Meat Processing Environment. Microbiol Spectr 2022; 10:e0135222. [PMID: 36194136 PMCID: PMC9602453 DOI: 10.1128/spectrum.01352-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Accepted: 09/09/2022] [Indexed: 12/30/2022] Open
Abstract
To explore the effect of beef processing on Escherichia coli populations in relation to lactic acid resistance, this study investigated the links among acid response, phylogenetic structure, genome diversity, and genotypes associated with acid resistance of meat plant E. coli. Generic E. coli isolates (n = 700) were from carcasses, fabrication equipment, and beef products. Acid treatment was carried out in Luria-Bertani broth containing 5.5% lactic acid (pH 2.9). Log reductions of E. coli ranged from <0.5 to >5 log CFU/mL (median: 1.37 log). No difference in lactic acid resistance was observed between E. coli populations recovered before and after a processing step or antimicrobial interventions. E. coli from the preintervention carcasses were slightly more resistant than E. coli isolated from equipment, differing by <0.5 log unit. Acid-resistant E. coli (log reduction <1, n = 45) had a higher prevalence of genes related to energy metabolism (ydj, xap, ato) and oxidative stress (fec, ymjC) than the less resistant E. coli (log reduction >1, n = 133). The ydj and ato operons were abundant in E. coli from preintervention carcasses. In contrast, fec genes were abundant in E. coli from equipment surfaces. The preintervention E. coli contained phylogroups A and B1 in relatively equal proportions. Phylogroup B1 predominated (95%) in the population from equipment. Of note, E. coli collected after sanitation shared either the antigens of O8 or H21. Additionally, genome diversity decreased after chilling and equipment sanitation. Overall, beef processing did not select for E. coli resistant to lactic acid but shaped the population structure. IMPORTANCE Antimicrobial interventions have significantly reduced the microbial loads on carcasses/meat products; however, the wide use of chemical and physical biocides has raised concerns over their potential for selecting resistant populations in the beef processing environment. Phenotyping of acid resistance and whole-genome analysis described in this study demonstrated beef processing practices led to differences in acid resistance, genotype, and population structure between carcass- and equipment-associated E. coli but did not select for the acid-resistant population. Results indicate that genes coding for the metabolism of long-chain sugar acids (ydj) and short-chain fatty acids (ato) were more prevalent in carcass-associated than equipment-associated E. coli. These results suggest E. coli from carcasses and equipment surfaces have been exposed to different selective pressures. The findings improve our understanding of the microbial ecology of E. coli in food processing environments and in general.
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Affiliation(s)
- Yuan Fang
- Agriculture and Agri-Food Canada Lacombe Research and Development Centre, Lacombe, Alberta, Canada
| | - Kim Stanford
- University of Lethbridge, Lethbridge, Alberta, Canada
| | - Xianqin Yang
- Agriculture and Agri-Food Canada Lacombe Research and Development Centre, Lacombe, Alberta, Canada
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7
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Hélaine V, Gastaldi C, Lemaire M, Clapés P, Guérard-Hélaine C. Recent Advances in the Substrate Selectivity of Aldolases. ACS Catal 2021. [DOI: 10.1021/acscatal.1c04273] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Virgil Hélaine
- Université Clermont Auvergne, CNRS, SIGMA Clermont, Institut de Chimie de Clermont-Ferrand, 63000 Clermont-Ferrand, France
| | - Cédric Gastaldi
- Université Clermont Auvergne, CNRS, SIGMA Clermont, Institut de Chimie de Clermont-Ferrand, 63000 Clermont-Ferrand, France
| | - Marielle Lemaire
- Université Clermont Auvergne, CNRS, SIGMA Clermont, Institut de Chimie de Clermont-Ferrand, 63000 Clermont-Ferrand, France
| | - Pere Clapés
- Biological Chemistry Department, Institute for Advanced Chemistry of Catalonia, IQAC−CSIC, 08034 Barcelona, Spain
| | - Christine Guérard-Hélaine
- Université Clermont Auvergne, CNRS, SIGMA Clermont, Institut de Chimie de Clermont-Ferrand, 63000 Clermont-Ferrand, France
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8
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Zhi Y, Xiang DF, Narindoshvili T, Andrews-Polymenis H, Raushel FM. Deciphering the Aldolase Function of STM3780 from a Bovine Enteric Infection-Related Gene Cluster in Salmonella enterica Serotype Typhimurium. Biochemistry 2020; 59:4573-4580. [PMID: 33231431 DOI: 10.1021/acs.biochem.0c00768] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Non-typhoidal Salmonella are capable of colonizing livestock and humans, where they can progressively cause disease. Previously, a library of targeted single-gene deletion mutants of Salmonella enterica serotype Typhimurium was inoculated to ligated ileal loops in calves to identify genes under selection. Of those genes identified, a cluster of genes is related to carbohydrate metabolism and transportation. It is proposed that an incoming carbohydrate is first phosphorylated by a phosphoenolpyruvate-dependent phosphotransferase system. The metabolite is further phosphorylated by the kinase STM3781 and then cleaved by the aldolase STM3780. STM3780 is functionally annotated as a class II fructose-bisphosphate aldolase. The aldolase was purified to homogeneity, and its aldol condensation activity with a range of aldehydes was determined. In the condensation reaction, STM3780 was shown to catalyze the abstraction of the pro-S hydrogen from C3 of dihydroxyacetone and subsequent formation of a carbon-carbon bond with S stereochemistry at C3 and R stereochemistry at C4. The best aldehyde substrate was identified as l-threouronate. Surprisingly, STM3780 was also shown to catalyze the condensation of two molecules of dihydroxyacetone phosphate to form the branched carbohydrate dendroketose bisphosphate.
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Affiliation(s)
- Yuan Zhi
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843, United States
| | - Dao Feng Xiang
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Tamari Narindoshvili
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Helene Andrews-Polymenis
- Department of Microbial Pathogenesis and Immunology, College of Medicine, Texas A&M University College of Medicine, Bryan, Texas 77807, United States
| | - Frank M Raushel
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843, United States.,Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
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9
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Stack TMM, Gerlt JA. Discovery of novel pathways for carbohydrate metabolism. Curr Opin Chem Biol 2020; 61:63-70. [PMID: 33197748 DOI: 10.1016/j.cbpa.2020.09.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 09/14/2020] [Accepted: 09/16/2020] [Indexed: 01/09/2023]
Abstract
Closing the gap between the increasing availability of complete genome sequences and the discovery of novel enzymes in novel metabolic pathways is a significant challenge. Here, we review recent examples of assignment of in vitro enzymatic activities and in vivo metabolic functions to uncharacterized proteins, with a focus on enzymes and metabolic pathways involved in the catabolism and biosynthesis of monosaccharides and polysaccharides. The most effective approaches are based on analyses of sequence-function space in protein families that provide clues for the predictions of the functions of the uncharacterized enzymes. As summarized in this Opinion, this approach allows the discovery of the catabolism of new molecules, new pathways for common molecules, and new enzymatic chemistries.
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Affiliation(s)
- Tyler M M Stack
- Carl. R. Woese Institute for Genomic Biology, University of Illinois, Urbana, IL 61801, United States
| | - John A Gerlt
- Carl. R. Woese Institute for Genomic Biology, University of Illinois, Urbana, IL 61801, United States; Departments of Biochemistry and Chemistry, University of Illinois, Urbana, IL 61801, United States.
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10
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Huddleston JP, Raushel FM. Functional Characterization of Cj1427, a Unique Ping-Pong Dehydrogenase Responsible for the Oxidation of GDP-d- glycero-α-d- manno-heptose in Campylobacter jejuni. Biochemistry 2020; 59:1328-1337. [PMID: 32168448 PMCID: PMC7500870 DOI: 10.1021/acs.biochem.0c00097] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The capsular polysaccharides (CPS) of Campylobacter jejuni contain multiple heptose residues with variable stereochemical arrangements at C3-C6. The immediate precursor to all of these possible variations is currently believed to be GDP-d-glycero-α-d-manno-heptose. Oxidation of this substrate at C4 enables subsequent epimerization reactions at C3-C5 that can be coupled to the dehydration/reduction at C5/C6. However, the enzyme responsible for the critical oxidation of C4 from GDP-d-glycero-α-d-manno-heptose has remained elusive. The enzyme Cj1427 from C. jejuni NCTC 11168 was shown to catalyze the oxidation of GDP-d-glycero-α-d-manno-heptose to GDP-d-glycero-4-keto-α-d-lyxo-heptose in the presence of α-ketoglutarate using mass spectrometry and nuclear magnetic resonance spectroscopy. At pH 7.4, the apparent kcat is 0.6 s-1, with a value of kcat/Km of 1.0 × 104 M-1 s-1 for GDP-d-glycero-α-d-manno-heptose. α-Ketoglutarate is required to recycle the tightly bound NADH nucleotide in the active site of Cj1427, which does not dissociate from the enzyme during catalysis.
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Affiliation(s)
- Jamison P. Huddleston
- Department of Chemistry, Texas A&M University, College Station, Texas, 77843, United States
| | - Frank M. Raushel
- Department of Chemistry, Texas A&M University, College Station, Texas, 77843, United States
- Department of Biochemistry & Biophysics, Texas A&M University, College Station, Texas 77843, United States
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11
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Huddleston JP, Anderson TK, Spencer KD, Thoden JB, Raushel FM, Holden HM. Structural Analysis of Cj1427, an Essential NAD-Dependent Dehydrogenase for the Biosynthesis of the Heptose Residues in the Capsular Polysaccharides of Campylobacter jejuni. Biochemistry 2020; 59:1314-1327. [PMID: 32168450 DOI: 10.1021/acs.biochem.0c00096] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Many strains of Campylobacter jejuni display modified heptose residues in their capsular polysaccharides (CPS). The precursor heptose was previously shown to be GDP-d-glycero-α-d-manno-heptose, from which a variety of modifications of the sugar moiety have been observed. These modifications include the generation of 6-deoxy derivatives and alterations of the stereochemistry at C3-C6. Previous work has focused on the enzymes responsible for the generation of the 6-deoxy derivatives and those involved in altering the stereochemistry at C3 and C5. However, the generation of the 6-hydroxyl heptose residues remains uncertain due to the lack of a specific enzyme to catalyze the initial oxidation at C4 of GDP-d-glycero-α-d-manno-heptose. Here we reexamine the previously reported role of Cj1427, a dehydrogenase found in C. jejuni NTCC 11168 (HS:2). We show that Cj1427 is co-purified with bound NADH, thus hindering catalysis of oxidation reactions. However, addition of a co-substrate, α-ketoglutarate, converts the bound NADH to NAD+. In this form, Cj1427 catalyzes the oxidation of l-2-hydroxyglutarate back to α-ketoglutarate. The crystal structure of Cj1427 with bound GDP-d-glycero-α-d-manno-heptose shows that the NAD(H) cofactor is ideally positioned to catalyze the oxidation at C4 of the sugar substrate. Additionally, the overall fold of the Cj1427 subunit places it into the well-defined short-chain dehydrogenase/reductase superfamily. The observed quaternary structure of the tetrameric enzyme, however, is highly unusual for members of this superfamily.
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Affiliation(s)
- Jamison P Huddleston
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Thomas K Anderson
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Keelan D Spencer
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - James B Thoden
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Frank M Raushel
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States.,Department of Biochemistry & Biophysics, Texas A&M University, College Station, Texas 77843, United States
| | - Hazel M Holden
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
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12
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Huddleston JP, Raushel FM. Biosynthesis of GDP-d- glycero-α-d- manno-heptose for the Capsular Polysaccharide of Campylobacter jejuni. Biochemistry 2019; 58:3893-3902. [PMID: 31449400 PMCID: PMC6859792 DOI: 10.1021/acs.biochem.9b00548] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The capsular polysaccharide (CPS) structure of Campylobacter jejuni contributes to its robust fitness. Many strains contain heptose moieties in their CPS units. The precursor heptose is GDP-d-glycero-α-d-manno-heptose; modifications to the stereochemistry at C3-C6 as well as additions of methyl and phosphoramidate groups lend to the hypervariability of the C. jejuni CPS structures. Synthesis of GDP-d-glycero-α-d-manno-heptose has been described previously, but using enzymes from Aneurinibacillus thermoaerophilus DSM 10155. Here we describe the complete synthesis of GDP-d-glycero-α-d-manno-heptose using enzymes from C. jejuni NTCC 11168: Cj1152 and Cj1423-Cj1425. Our results yield kinetic parameters for these enzymes and outline a successful strategy for milligram-gram scale synthesis of GDP-d-glycero-α-d-manno-heptose. This achievement is critical for the characterization of other carbohydrate tailoring enzymes, which are expected to utilize GDP-d-glycero-α-d-manno-heptose for the biosynthesis of more complex carbohydrates in the CPS of C. jejuni.
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Affiliation(s)
- Jamison P Huddleston
- Department of Chemistry , Texas A&M University , College Station , Texas 77843 , United States
| | - Frank M Raushel
- Department of Chemistry , Texas A&M University , College Station , Texas 77843 , United States
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13
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Huddleston JP, Raushel FM. Functional Characterization of YdjH, a Sugar Kinase of Unknown Specificity in Escherichia coli K12. Biochemistry 2019; 58:3354-3364. [PMID: 31314509 DOI: 10.1021/acs.biochem.9b00327] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The ydj gene cluster is annotated to catalyze the catabolism of an unknown carbohydrate. Previously, YdjI, a class II aldolase, was shown to catalyze the retro-aldol cleavage of l-glycero-l-galacto-octuluronate-1-phosphate into DHAP and l-arabinuronate. In this report, the functional characterization of YdjH is presented. YdjH catalyzes the phosphorylation of 2-keto-monosaccharides at the C1 hydroxyl group with a substrate profile significantly more stringent than that of YdjI. Similar to YdjI, YdjH shows a strong preference for higher-order monosaccharides (seven to nine carbons) with a carboxylate terminus. The best substrate was determined to be l-glycero-l-galacto-octuluronate, yielding l-glycero-l-galacto-octuluronate-1-phosphate with a kcat of 16 s-1 and a kcat/Km of 2.1 × 104 M-1 s-1. This is apparently the first reported example of kinase activity with eight-carbon monosaccharides. Two crystal structures of YdjH were previously determined to 2.15 and 1.8 Å resolution (Protein Data Bank entries 3H49 and 3IN1 ). We present an analysis of the active site layout and use computational docking to identify potential key residues in the binding of l-glycero-l-galacto-octuluronate.
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Affiliation(s)
- Jamison P Huddleston
- Department of Chemistry , Texas A&M University , College Station , Texas 77843 , United States
| | - Frank M Raushel
- Department of Chemistry , Texas A&M University , College Station , Texas 77843 , United States
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