1
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Plaza-Pegueroles A, Aphasizheva I, Aphasizhev R, Fernández-Tornero C, Ruiz FM. The cryo-EM structure of trypanosome 3-methylcrotonyl-CoA carboxylase provides mechanistic and dynamic insights into its enzymatic function. Structure 2024; 32:930-940.e3. [PMID: 38593794 PMCID: PMC11246232 DOI: 10.1016/j.str.2024.03.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Revised: 02/15/2024] [Accepted: 03/13/2024] [Indexed: 04/11/2024]
Abstract
3-Methylcrotonyl-CoA carboxylase (MCC) catalyzes the two-step, biotin-dependent production of 3-methylglutaconyl-CoA, an essential intermediate in leucine catabolism. Given the critical metabolic role of MCC, deficiencies in this enzyme lead to organic aciduria, while its overexpression is linked to tumor development. MCC is a dodecameric enzyme composed of six copies of each α- and β-subunit. We present the cryo-EM structure of the endogenous MCC holoenzyme from Trypanosoma brucei in a non-filamentous state at 2.4 Å resolution. Biotin is covalently bound to the biotin carboxyl carrier protein domain of α-subunits and positioned in a non-canonical pocket near the active site of neighboring β-subunit dimers. Moreover, flexibility of key residues at α-subunit interfaces and loops enables pivoting of α-subunit trimers to partly reduce the distance between α- and β-subunit active sites, required for MCC catalysis. Our results provide a structural framework to understand the enzymatic mechanism of eukaryotic MCCs and to assist drug discovery against trypanosome infections.
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Affiliation(s)
| | - Inna Aphasizheva
- Department of Molecular and Cell Biology, Boston University Medical Campus (BUMC), Boston, MA 02118, USA
| | - Ruslan Aphasizhev
- Department of Molecular and Cell Biology, Boston University Medical Campus (BUMC), Boston, MA 02118, USA
| | | | - Federico M Ruiz
- Centro de Investigaciones Biológicas Margarita Salas (CIB), CSIC, 28040 Madrid, Spain.
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2
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Zimmermann J, Mayer RJ, Moran J. A single phosphorylation mechanism in early metabolism - the case of phosphoenolpyruvate. Chem Sci 2023; 14:14100-14108. [PMID: 38098731 PMCID: PMC10717536 DOI: 10.1039/d3sc04116f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Accepted: 11/22/2023] [Indexed: 12/17/2023] Open
Abstract
Phosphorylation is thought to be one of the fundamental reactions for the emergence of metabolism. Nearly all enzymatic phosphorylation reactions in the anabolic core of microbial metabolism act on carboxylates to give acyl phosphates, with a notable exception - the phosphorylation of pyruvate to phosphoenolpyruvate (PEP), which involves an enolate. We wondered whether an ancestral mechanism for the phosphorylation of pyruvate to PEP could also have involved carboxylate phosphorylation rather than the modern enzymatic form. The phosphorylation of pyruvate with P4O10 as a model phosphorylating agent was found to indeed occur via carboxylate phosphorylation, as verified by mechanistic studies using model substrates, time course experiments, liquid and solid-state NMR spectroscopy, and DFT calculations. The in situ generated acyl phosphate subsequently undergoes an intramolecular phosphoryl transfer to yield PEP. A single phosphorylation mechanism acting on carboxylates appears sufficient to initiate metabolic networks that include PEP, strengthening the case that metabolism emerged from self-organized chemistry.
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Affiliation(s)
- Joris Zimmermann
- Institut de Science et d'Ingénierie Supramoléculaires (ISIS), CNRS UMR 7006, Université de Strasbourg 8 Allée Gaspard Monge 67000 Strasbourg France
| | - Robert J Mayer
- Institut de Science et d'Ingénierie Supramoléculaires (ISIS), CNRS UMR 7006, Université de Strasbourg 8 Allée Gaspard Monge 67000 Strasbourg France
| | - Joseph Moran
- Institut de Science et d'Ingénierie Supramoléculaires (ISIS), CNRS UMR 7006, Université de Strasbourg 8 Allée Gaspard Monge 67000 Strasbourg France
- Institut Universitaire de France (IUF) France
- Department of Chemistry and Biomolecular Sciences, University of Ottawa Ottawa Ontario K1N 6N5 Canada
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3
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CryoEM structural exploration of catalytically active enzyme pyruvate carboxylase. Nat Commun 2022; 13:6185. [PMID: 36261450 PMCID: PMC9581989 DOI: 10.1038/s41467-022-33987-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Accepted: 10/04/2022] [Indexed: 12/24/2022] Open
Abstract
Pyruvate carboxylase (PC) is a tetrameric enzyme that contains two active sites per subunit that catalyze two consecutive reactions. A mobile domain with an attached prosthetic biotin links both reactions, an initial biotin carboxylation and the subsequent carboxyl transfer to pyruvate substrate to produce oxaloacetate. Reaction sites are at long distance, and there are several co-factors that play as allosteric regulators. Here, using cryoEM we explore the structure of active PC tetramers focusing on active sites and on the conformational space of the oligomers. The results capture the mobile domain at both active sites and expose catalytic steps of both reactions at high resolution, allowing the identification of substrates and products. The analysis of catalytically active PC tetramers reveals the role of certain motions during enzyme functioning, and the structural changes in the presence of additional cofactors expose the mechanism for allosteric regulation.
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4
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Santamaria G, Ruiz-Rodriguez P, Renau-Mínguez C, Pinto FR, Coscollá M. In Silico Exploration of Mycobacterium tuberculosis Metabolic Networks Shows Host-Associated Convergent Fluxomic Phenotypes. Biomolecules 2022; 12:376. [PMID: 35327567 PMCID: PMC8945471 DOI: 10.3390/biom12030376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 01/29/2022] [Accepted: 02/22/2022] [Indexed: 02/04/2023] Open
Abstract
Mycobacterium tuberculosis, the causative agent of tuberculosis, is composed of several lineages characterized by a genome identity higher than 99%. Although the majority of the lineages are associated with humans, at least four lineages are adapted to other mammals, including different M. tuberculosis ecotypes. Host specificity is associated with higher virulence in its preferred host in ecotypes such as M. bovis. Deciphering what determines the preference of the host can reveal host-specific virulence patterns. However, it is not clear which genomic determinants might be influencing host specificity. In this study, we apply a combination of unsupervised and supervised classification methods on genomic data of ~27,000 M. tuberculosis clinical isolates to decipher host-specific genomic determinants. Host-specific genomic signatures are scarce beyond known lineage-specific mutations. Therefore, we integrated lineage-specific mutations into the iEK1011 2.0 genome-scale metabolic model to obtain lineage-specific versions of it. Flux distributions sampled from the solution spaces of these models can be accurately separated according to host association. This separation correlated with differences in cell wall processes, lipid, amino acid and carbon metabolic subsystems. These differences were observable when more than 95% of the samples had a specific growth rate significantly lower than the maximum achievable by the models. This suggests that these differences might manifest at low growth rate settings, such as the restrictive conditions M. tuberculosis suffers during macrophage infection.
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Affiliation(s)
- Guillem Santamaria
- ISysBio, University of Valencia-FISABIO Joint Unit, 46980 Paterna, Spain; (G.S.); (P.R.-R.); (C.R.-M.)
- BioISI—Biosciences & Integrative Sciences Institute, Faculty of Sciences, University of Lisboa, 1749-016 Lisboa, Portugal
| | - Paula Ruiz-Rodriguez
- ISysBio, University of Valencia-FISABIO Joint Unit, 46980 Paterna, Spain; (G.S.); (P.R.-R.); (C.R.-M.)
| | - Chantal Renau-Mínguez
- ISysBio, University of Valencia-FISABIO Joint Unit, 46980 Paterna, Spain; (G.S.); (P.R.-R.); (C.R.-M.)
| | - Francisco R. Pinto
- BioISI—Biosciences & Integrative Sciences Institute, Faculty of Sciences, University of Lisboa, 1749-016 Lisboa, Portugal
| | - Mireia Coscollá
- ISysBio, University of Valencia-FISABIO Joint Unit, 46980 Paterna, Spain; (G.S.); (P.R.-R.); (C.R.-M.)
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5
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A novel pneumococcal protein-polysaccharide conjugate vaccine based on biotin-streptavidin. Infect Immun 2021; 90:e0035221. [PMID: 34694917 DOI: 10.1128/iai.00352-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Pneumococcal disease is a serious public health problem worldwide and an important cause of morbidity and mortality among children and adults in developing countries. Although vaccination is among the most effective approaches to prevent and control pneumococcal diseases, approved vaccines have limited protective effects. We developed a pneumococcal protein-polysaccharide conjugate vaccine that is mediated by the non-covalent interaction between biotin and streptavidin. Biotinylated type IV capsular polysaccharide was incubated with a fusion protein containing core streptavidin and Streptococcus pneumoniae virulence protein and relying on the non-covalent interaction between biotin and streptavidin to prepare the protein-polysaccharide conjugate vaccine. Analysis of vaccine efficacy revealed that mice immunized with the protein-polysaccharide conjugate vaccine produced antibodies with high potency against virulence proteins and polysaccharide antigens and were able to induce Th1 and Th17 responses. The antibodies identified using an opsonophagocytic assay were capable of activating the complement system and promoting pathogen elimination by phagocytes. Additionally, mice immunized with the protein-polysaccharide conjugate vaccine and then infected with a lethal dose of Streptococcus pneumoniae demonstrated induced protective immunity. The data indicated that the pneumococcal protein-polysaccharide (biotin-streptavidin) conjugate vaccine demonstrated broad-spectrum activity applicable to a wide range of people and ease of direct coupling between protein and polysaccharide. These findings provide further evidence for the application of biotin-streptavidin in S. pneumoniae vaccines.
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6
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Xie X, Spiteller D, Huhn T, Schink B, Müller N. Desulfatiglans anilini Initiates Degradation of Aniline With the Production of Phenylphosphoamidate and 4-Aminobenzoate as Intermediates Through Synthases and Carboxylases From Different Gene Clusters. Front Microbiol 2020; 11:2064. [PMID: 33013754 PMCID: PMC7500099 DOI: 10.3389/fmicb.2020.02064] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 08/05/2020] [Indexed: 01/22/2023] Open
Abstract
The anaerobic degradation of aniline was studied in the sulfate-reducing bacterium Desulfatiglans anilini. Our aim was to identify the genes and their proteins that are required for the initial activation of aniline as well as to characterize intermediates of this reaction. Aniline-induced genes were revealed by comparison of the proteomes of D. anilini grown with different substrates (aniline, 4-aminobenzoate, phenol, and benzoate). Most genes encoding proteins that were highly abundant in aniline- or 4-aminobenzoate-grown D. anilini cells but not in phenol- or benzoate-grown cells were located in the putative gene clusters ani (aniline degradation), hcr (4-hydroxybenzoyl-CoA reductase) and phe (phenol degradation). Of these putative gene clusters, only the phe gene cluster has been studied previously. Based on the differential proteome analysis, four candidate genes coding for kinase subunits and carboxylase subunits were suspected to be responsible for the initial conversion of aniline to 4-aminobenzoate. These genes were cloned and overproduced in E. coli. The recombinant proteins were obtained in inclusion bodies but could be refolded successfully. Two subunits of phenylphosphoamidate synthase and two carboxylase subunits converted aniline to 4-aminobenzoate with phenylphosphoamidate as intermediate under consumption of ATP. Only when both carboxylase subunits, one from gene cluster ani and the other from gene cluster phe, were combined, phenylphosphoamidate was converted to 4-aminobenzoate in vitro, with Mn2+, K+, and FMN as co-factors. Thus, aniline is degraded by the anaerobic bacterium D. anilini only by recruiting genes for the enzymatic machinery from different gene clusters. We conclude, that D. anilini carboxylates aniline to 4-aminobenzoate via phenylphosphoamidate as an energy rich intermediate analogous to the degradation of phenol to 4-hydroxybenzoate via phenylphosphate.
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Affiliation(s)
- Xiaoman Xie
- Department of Biology, Universität Konstanz, Konstanz, Germany.,Konstanz Research School Chemical Biology, Konstanz, Germany
| | - Dieter Spiteller
- Department of Biology, Universität Konstanz, Konstanz, Germany.,Konstanz Research School Chemical Biology, Konstanz, Germany
| | - Thomas Huhn
- Konstanz Research School Chemical Biology, Konstanz, Germany.,Department of Chemistry, Universität Konstanz, Konstanz, Germany
| | - Bernhard Schink
- Department of Biology, Universität Konstanz, Konstanz, Germany.,Konstanz Research School Chemical Biology, Konstanz, Germany
| | - Nicolai Müller
- Department of Biology, Universität Konstanz, Konstanz, Germany
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7
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Zeng Q, Yang Q, Jia J, Bi H. A Moraxella Virulence Factor Catalyzes an Essential Esterase Reaction of Biotin Biosynthesis. Front Microbiol 2020; 11:148. [PMID: 32117167 PMCID: PMC7026016 DOI: 10.3389/fmicb.2020.00148] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Accepted: 01/22/2020] [Indexed: 11/13/2022] Open
Abstract
Pimeloyl-acyl carrier protein (ACP) methyl ester esterase catalyzes the last biosynthetic step of the pimelate moiety of biotin, a key intermediate in biotin biosynthesis. The paradigm pimeloyl-ACP methyl ester esterase is the BioH protein of Escherichia coli that hydrolyses the ester bond of pimeloyl-ACP methyl ester. Biotin synthesis in E. coli also requires the function of the malonyl-ACP methyltransferase gene (bioC) to employ a methylation strategy to allow elongation of a temporarily disguised malonate moiety to a pimelate moiety by the fatty acid synthetic enzymes. However, bioinformatics analyses of the extant bacterial genomes showed that bioH is absent in many bioC-containing bacteria. The genome of the Gram-negative bacterium, Moraxella catarrhalis lacks a gene encoding a homolog of any of the six known pimeloyl-ACP methyl ester esterase isozymes suggesting that this organism encodes a novel pimeloyl-ACP methyl ester esterase isoform. We report that this is the case. The gene encoding the new isoform, called btsA, was isolated by complementation of an E. coli bioH deletion strain. The requirement of BtsA for the biotin biosynthesis in M. catarrhalis was confirmed by a biotin auxotrophic phenotype caused by deletion of btsA in vivo and a reconstituted in vitro desthiobiotin synthesis system. Purified BtsA was shown to cleave the physiological substrate pimeloyl-ACP methyl ester to pimeloyl-ACP by use of a Ser117-His254-Asp287 catalytic triad. The lack of sequence alignment with other isozymes together with phylogenetic analyses revealed BtsA as a new class of pimeloyl-ACP methyl ester esterase. The involvement of BtsA in M. catarrhalis virulence was confirmed by the defect of bacterial invasion to lung epithelial cells and survival within macrophages in the ΔbtsA strains. Identification of the new esterase gene btsA exclusive in Moraxella species that links biotin biosynthesis to bacterial virulence, can reveal a new valuable target for development of drugs against M. catarrhalis.
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Affiliation(s)
- Qi Zeng
- Jiangsu Key Laboratory of Pathogen Biology, Department of Pathogen Biology, Nanjing Medical University, Nanjing, China
| | - Qi Yang
- Jiangsu Key Laboratory of Pathogen Biology, Department of Pathogen Biology, Nanjing Medical University, Nanjing, China
| | - Jia Jia
- Jiangsu Key Laboratory of Pathogen Biology, Department of Pathogen Biology, Nanjing Medical University, Nanjing, China
| | - Hongkai Bi
- Jiangsu Key Laboratory of Pathogen Biology, Department of Pathogen Biology, Nanjing Medical University, Nanjing, China
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8
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Wang L, Chen Y, Shang F, Liu W, Lan J, Gao P, Ha NC, Nam KH, Dong Y, Quan C, Xu Y. Structural insight into the carboxylesterase BioH from Klebsiella pneumoniae. Biochem Biophys Res Commun 2019; 520:538-543. [PMID: 31615653 DOI: 10.1016/j.bbrc.2019.10.050] [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: 09/27/2019] [Accepted: 10/04/2019] [Indexed: 10/25/2022]
Abstract
The BioH carboxylesterase which is a typical α/β-hydrolase enzyme involved in biotin synthetic pathway in most bacteria. BioH acts as a gatekeeper and blocks the further elongation of its substrate. In the pathogen Klebsiella pneumoniae, BioH plays a critical role in the biosynthesis of biotin. To better understand the molecular function of BioH, we determined the crystal structure of BioH from K. pneumoniae at 2.26 Å resolution using X-ray crystallography. The structure of KpBioH consists of an α-β-α sandwich domain and a cap domain. B-factor analysis revealed that the α-β-α sandwich domain is a rigid structure, while the loops in the cap domain shows the structural flexibility. The active site of KpBioH contains the catalytic triad (Ser82-Asp207-His235) on the interface of the α-β-α sandwich domain, which is surrounded by the cap domain. Size exclusion chromatography shows that KpBioH prefers the monomeric state in solution, whereas two-fold symmetric dimeric formation of KpBioH was observed in the asymmetric unit, the conserved Cys31-based disulfide bonds can maintain the irreversible dimeric formation of KpBioH. Our study provides important structural insight for understanding the molecular mechanisms of KpBioH and its homologous proteins.
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Affiliation(s)
- Lulu Wang
- School of Life Science and Biotechnology, Dalian University of Technology, No 2 Linggong Road, Dalian, 116024, Liaoning, China; Department of Bioengineering, College of Life Science, Dalian Minzu University, Dalian, 116600, Liaoning, China; Key Laboratory of Biotechnology and Bioresources Utilization (Dalian Minzu University), Ministry of Education, China
| | - Yuanyuan Chen
- Department of Bioengineering, College of Life Science, Dalian Minzu University, Dalian, 116600, Liaoning, China; Key Laboratory of Biotechnology and Bioresources Utilization (Dalian Minzu University), Ministry of Education, China
| | - Fei Shang
- Department of Bioengineering, College of Life Science, Dalian Minzu University, Dalian, 116600, Liaoning, China; Key Laboratory of Biotechnology and Bioresources Utilization (Dalian Minzu University), Ministry of Education, China
| | - Wei Liu
- Department of Bioengineering, College of Life Science, Dalian Minzu University, Dalian, 116600, Liaoning, China; Key Laboratory of Biotechnology and Bioresources Utilization (Dalian Minzu University), Ministry of Education, China
| | - Jing Lan
- Department of Bioengineering, College of Life Science, Dalian Minzu University, Dalian, 116600, Liaoning, China; Key Laboratory of Biotechnology and Bioresources Utilization (Dalian Minzu University), Ministry of Education, China
| | - Peng Gao
- Clinical Laboratory, Dalian Sixth People's Hospital, Dalian, 116001, Liaoning, China
| | - Nam-Chul Ha
- Department of Agricultural Biotechnology, College of Agriculture and Life Sciences, Seoul National University, Gwanak-gu, Seoul, 08826, Republic of Korea
| | - Ki Hyun Nam
- Division of Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul, 02841, Republic of Korea
| | - Yuesheng Dong
- School of Life Science and Biotechnology, Dalian University of Technology, No 2 Linggong Road, Dalian, 116024, Liaoning, China.
| | - Chunshan Quan
- Department of Bioengineering, College of Life Science, Dalian Minzu University, Dalian, 116600, Liaoning, China; Key Laboratory of Biotechnology and Bioresources Utilization (Dalian Minzu University), Ministry of Education, China.
| | - Yongbin Xu
- Department of Bioengineering, College of Life Science, Dalian Minzu University, Dalian, 116600, Liaoning, China; Key Laboratory of Biotechnology and Bioresources Utilization (Dalian Minzu University), Ministry of Education, China.
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9
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Kwon KM, Bekal S, Domier LL, Lambert KN. Active and inactive forms of biotin synthase occur in Heterodera glycines. J Nematol 2019; 51:e2019-69. [PMID: 34179812 PMCID: PMC6909392 DOI: 10.21307/jofnem-2019-069] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Indexed: 11/11/2022] Open
Abstract
Heterodera glycines, the soybean cyst nematode (SCN), is a plant-parasitic nematode capable of manipulating host plant biochemistry and development. Many studies have suggested that the nematode has acquired genes from bacteria via horizontal gene transfer events (HGTs) that have the potential to enhance nematode parasitism. A recent allelic imbalance analysis identified two candidate virulence genes, which also appear to have entered the SCN genome through HGTs. One of the candidate genes, H. glycines biotin synthase (HgBioB), contained sequence polymorphisms between avirulent and virulent inbred SCN strains. To test the function of these HgBioB alleles, a complementation experiment using biotin synthase-deficient Escherichia coli was conducted. Here, we report that avirulent nematodes produce an active biotin synthase while virulent ones contain an inactive form of the enzyme. Moreover, sequencing analysis of HgBioB genes from SCN field populations indicates the presence of diverse mixture of HgBioB alleles with the virulent form being the most prevalent. We hypothesize that the mutations in the inactive HgBioB allele within the virulent SCN could result in a change in protein function that in some unknown way bolster its parasitic lifestyle.
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Affiliation(s)
- Khee Man Kwon
- Department of Crop Sciences, University of Illinois, Urbana, IL.,Department of Plant Pathology and Center for Applied Genetic Technologies, University of Georgia, Athens, GA
| | - Sadia Bekal
- Department of Agricultural and Biological Engineering, University of Illinois, Urbana, IL
| | - Leslie L Domier
- Department of Crop Sciences, University of Illinois, Urbana, IL.,United States Department of Agriculture - Agricultural Research Service, Urbana, IL
| | - Kris N Lambert
- Department of Crop Sciences, University of Illinois, Urbana, IL
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10
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Wang X, Li Y, Chen X, Zhou Z, Yao J. Human Acetyl-CoA Carboxylase 1 Is an Isomerase: Carboxyl Transfer Is Activated by Catalytic Effect of Isomerization. J Phys Chem B 2019; 123:6757-6764. [PMID: 31306022 DOI: 10.1021/acs.jpcb.9b05384] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Obesity and its related diseases such as cancer and diabetes are leading life-threatening issues in the modern world. Thus, new drugs toward obesity and obesity-caused diseases are highly desired. Human acetyl-CoA carboxylase 1 (hACC1) in charge of the rate-limiting step of the human fatty acid synthesis was recognized as an attractive target for rational drug design. The fundamental reaction mechanism and nature of the transition state of hACC1 remain unclear. In this study, combined quantum mechanics and molecular mechanics (QM/MM), molecular dynamics (MD), and free-energy simulations were performed to investigate the catalytic mechanism of the hACC1-catalyzed carboxyl-transfer reaction. Our computational results show a three-step mechanism for carboxyl transferase (CT)-catalyzed reaction, including isomerization of carboxybiotin, proton-transfer from acetyl-CoA to carboxybiotin, and carboxylation of acetyl-CoA enolate. Interestingly, isomerization of carboxybiotin is the rate-limiting step of the entire reaction pathway, indicating hACC1 has the catalytic effect of isomerization and thus might be an isomerase also. The activation free-energy barrier of carboxyl-transfer catalyzed by hACC1 was calculated to be 16.4 kcal/mol, in excellent agreement with the experimental result (16.7 kcal/mol). The obtained reaction mechanism together with the nature of the transition state provides helpful knowledge not only for future investigation of other ACCs but also for rational design of hACC1 inhibitors, such as TS analogue. The catalytic effect of hACC1 isomerization is discussed.
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Affiliation(s)
- Xia Wang
- School of Biological Science and Technology , University of Jinan , Jinan 250022 , China
| | - Yajing Li
- Department of Clinical Laboratory , The Second Hospital of Hebei Medical University , Shijiazhuang 050000 , China
| | - Xiabin Chen
- Holistic Integrative Pharmacy Institutes (HIPI), School of Medicine , Hangzhou Normal University , Hangzhou 311121 , China
| | - Ziyuan Zhou
- Department of Chemical Biology, School of Chemical Biology and Biotechnology , Shenzhen Graduate School of Peking University , Shenzhen 518055 , China
| | - Jianzhuang Yao
- School of Biological Science and Technology , University of Jinan , Jinan 250022 , China
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11
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Functional Replacement of the BioC and BioH Proteins of Escherichia coli Biotin Precursor Biosynthesis by Ehrlichia chaffeensis Novel Proteins. Curr Microbiol 2019; 76:626-636. [PMID: 30915508 DOI: 10.1007/s00284-019-01669-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Accepted: 03/05/2019] [Indexed: 01/22/2023]
Abstract
The biosynthesis of the pimelate moiety of biotin in Escherichia coli requires two specialized proteins, BioC and BioH. However, the enzymes that have BioC- or BioH-like activities show remarkable sequence diversity among biotin-producing bacteria. Here, we report that the intracellular rickettsial pathogen Ehrlichia chaffeensis encodes two novel proteins, BioT and BioU, which functionally replace the E. coli BioC and BioH proteins, respectively. The desthiobiotin assays demonstrated that these two proteins make pimeloyl-acyl carrier protein (ACP) from the substrate malonyl-ACP with the aid of the FAS II pathway, through the expected pimeloyl-ACP methyl ester intermediate. BioT and BioU homologues seem restricted to the species of Ehrlichia and its close relative, Anaplasma. Taken together, the synthesis of the biotin precursor in E. chaffeensis appears to be catalyzed by two novel BioC- and BioH-like proteins.
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12
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Tomassetti M, Garavaglia BS, Vranych CV, Gottig N, Ottado J, Gramajo H, Diacovich L. 3-methylcrotonyl Coenzyme A (CoA) carboxylase complex is involved in the Xanthomonas citri subsp. citri lifestyle during citrus infection. PLoS One 2018; 13:e0198414. [PMID: 29879157 PMCID: PMC5991677 DOI: 10.1371/journal.pone.0198414] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Accepted: 05/19/2018] [Indexed: 01/15/2023] Open
Abstract
Citrus canker is a disease caused by the phytopathogen Xanthomonas citri subsp. citri (Xcc), bacterium which is unable to survive out of the host for extended periods of time. Once established inside the plant, the pathogen must compete for resources and evade the defenses of the host cell. However, a number of aspects of Xcc metabolic and nutritional state, during the epiphytic stage and at different phases of infection, are poorly characterized. The 3-methylcrotonyl-CoA carboxylase complex (MCC) is an essential enzyme for the catabolism of the branched-chain amino acid leucine, which prevents the accumulation of toxic intermediaries, facilitates the generation of branched chain fatty acids and/or provides energy to the cell. The MCC complexes belong to a group of acyl-CoA carboxylases (ACCase) enzymes dependent of biotin. In this work, we have identified two ORFs (XAC0263 and XAC0264) encoding for the α and β subunits of an acyl-CoA carboxylase complex from Xanthomonas and demonstrated that this enzyme has MCC activity both in vitro and in vivo. We also found that this MCC complex is conserved in a group of pathogenic gram negative bacteria. The generation and analysis of an Xcc mutant strain deficient in MCC showed less canker lesions in the interaction with the host plant, suggesting that the expression of these proteins is necessary for Xcc fitness during infection.
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Affiliation(s)
- Mauro Tomassetti
- Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Betiana S. Garavaglia
- Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Cecilia V. Vranych
- Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Natalia Gottig
- Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Jorgelina Ottado
- Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Hugo Gramajo
- Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Lautaro Diacovich
- Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
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13
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Plasch K, Hofer G, Keller W, Hay S, Heyes DJ, Dennig A, Glueck SM, Faber K. Pressurized CO 2 as a carboxylating agent for the biocatalytic ortho-carboxylation of resorcinol. GREEN CHEMISTRY : AN INTERNATIONAL JOURNAL AND GREEN CHEMISTRY RESOURCE : GC 2018; 20:1754-1759. [PMID: 29780282 PMCID: PMC5942041 DOI: 10.1039/c8gc00008e] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/01/2018] [Accepted: 03/08/2018] [Indexed: 05/25/2023]
Abstract
The utilization of gaseous carbon dioxide instead of bicarbonate would greatly facilitate process development for enzyme catalyzed carboxylations on a large scale. As a proof-of-concept, 1,3-dihydroxybenzene (resorcinol) was carboxylated in the ortho-position using pressurized CO2 (∼30-40 bar) catalyzed by ortho-benzoic acid decarboxylases with up to 68% conversion. Optimization studies revealed tight pH-control and enzyme stability as the most important determinants.
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Affiliation(s)
- Katharina Plasch
- Department of Chemistry , Organic & Bioorganic Chemistry , University of Graz , Heinrichstrasse 28 , 8010 Graz , Austria . ;
| | - Gerhard Hofer
- Institute of Molecular Biosciences , University of Graz , Humboldstrasse 50 , 8010 Graz , Austria
| | - Walter Keller
- Institute of Molecular Biosciences , University of Graz , Humboldstrasse 50 , 8010 Graz , Austria
| | - Sam Hay
- Manchester Institute of Biotechnology , University of Manchester , 131 Princess Street , Manchester M1 7DN , UK
| | - Derren J Heyes
- Manchester Institute of Biotechnology , University of Manchester , 131 Princess Street , Manchester M1 7DN , UK
| | - Alexander Dennig
- Institute of Biotechnology and Biochemical Engineering , Graz University of Technology , Petersgasse 12 , 8010 Graz , Austria
| | - Silvia M Glueck
- Department of Chemistry , Organic & Bioorganic Chemistry , University of Graz , Heinrichstrasse 28 , 8010 Graz , Austria . ;
- Austrian Centre of Industrial Biotechnology (ACIB) , Petersgasse 14 , 8010 Graz , Austria
| | - Kurt Faber
- Department of Chemistry , Organic & Bioorganic Chemistry , University of Graz , Heinrichstrasse 28 , 8010 Graz , Austria . ;
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14
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Structure and function of urea amidolyase. Biosci Rep 2018; 38:BSR20171617. [PMID: 29263142 PMCID: PMC5770610 DOI: 10.1042/bsr20171617] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Revised: 12/16/2017] [Accepted: 12/19/2017] [Indexed: 11/25/2022] Open
Abstract
Urea is the degradation product of a wide range of nitrogen containing bio-molecules. Urea amidolyase (UA) catalyzes the conversion of urea to ammonium, the essential first step in utilizing urea as a nitrogen source. It is widely distributed in fungi, bacteria and other microorganisms, and plays an important role in nitrogen recycling in the biosphere. UA is composed of urea carboxylase (UC) and allophanate hydrolase (AH) domains, which catalyze sequential reactions. In some organisms UC and AH are encoded by separated genes. We present here structure of the Kluyveromyces lactis UA (KlUA). The structure revealed that KlUA forms a compact homo-dimer with a molecular weight of 400 kDa. Structure inspired biochemical experiments revealed the mechanism of its reaction intermediate translocation, and that the KlUA holo-enzyme formation is essential for its optimal activity. Interestingly, previous studies and ours suggest that UC and AH encoded by separated genes probably do not form a KlUA-like complex, consequently they might not catalyze the urea to ammonium conversion as efficiently.
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15
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Bahal RK, Mathur S, Chauhan P, Tyagi AK. An attenuated quadruple gene mutant of Mycobacterium tuberculosis imparts protection against tuberculosis in guinea pigs. Biol Open 2018; 7:bio.029546. [PMID: 29242198 PMCID: PMC5829500 DOI: 10.1242/bio.029546] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Previously we had developed a triple gene mutant of Mycobacterium tuberculosis (MtbΔmms) harboring disruption in three genes, namely mptpA, mptpB and sapM. Though vaccination with MtbΔmms strain induced protection in the lungs of guinea pigs, the mutant strain failed to control the hematogenous spread of the challenge strain to the spleen. Additionally, inoculation with MtbΔmms resulted in some pathological damage to the spleens in the early phase of infection. In order to generate a strain that overcomes the pathology caused by MtbΔmms in spleen of guinea pigs and controls dissemination of the challenge strain, MtbΔmms was genetically modified by disrupting bioA gene to generate MtbΔmmsb strain. Further, in vivo attenuation of MtbΔmmsb was evaluated and its protective efficacy was assessed against virulent M. tuberculosis challenge in guinea pigs. MtbΔmmsb mutant strain was highly attenuated for growth and virulence in guinea pigs. Vaccination with MtbΔmmsb mutant generated significant protection in comparison to sham-immunized animals at 4 and 12 weeks post-infection in lungs and spleen of infected animals. However, the protection imparted by MtbΔmmsb was significantly less in comparison to BCG immunized animals. This study indicates the importance of attenuated multiple gene deletion mutants of M. tuberculosis for generating protection against tuberculosis. Summary: In this study, a mutant of M. tuberculosis with the deletion of four important genes has been evaluated in guinea pigs for its attenuation and protective efficacy against tuberculosis.
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Affiliation(s)
- Ritika Kar Bahal
- Department of Biochemistry, University of Delhi South Campus, Benito Juarez Road, New Delhi 110021, India
| | - Shubhita Mathur
- Department of Biochemistry, University of Delhi South Campus, Benito Juarez Road, New Delhi 110021, India
| | - Priyanka Chauhan
- Department of Biochemistry, University of Delhi South Campus, Benito Juarez Road, New Delhi 110021, India
| | - Anil K Tyagi
- Department of Biochemistry, University of Delhi South Campus, Benito Juarez Road, New Delhi 110021, India .,Guru Gobind Singh Indraprastha University, Sector 16-C, Dwarka, New Delhi 110078, India
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16
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Cepeda J, Beobide G, Castillo O, Luque A, Pérez-Yáñez S. Structural diversity of coordination compounds derived from double-chelating and planar diazinedicarboxylate ligands. Coord Chem Rev 2017. [DOI: 10.1016/j.ccr.2017.08.025] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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17
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Vallejo Esquerra E, Yang H, Sanchez SE, Omsland A. Physicochemical and Nutritional Requirements for Axenic Replication Suggest Physiological Basis for Coxiella burnetii Niche Restriction. Front Cell Infect Microbiol 2017; 7:190. [PMID: 28620582 PMCID: PMC5449765 DOI: 10.3389/fcimb.2017.00190] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Accepted: 05/02/2017] [Indexed: 11/13/2022] Open
Abstract
Bacterial obligate intracellular parasites are clinically significant animal and human pathogens. Central to the biology of these organisms is their level of adaptation to intracellular replication niches associated with physicochemical and nutritional constraints. While most bacterial pathogens can adapt to a wide range of environments, severe niche restriction-an inability to thrive in diverse environments-is a hallmark of bacterial obligate intracellular parasites. Herein the physicochemical and nutritional factors underlying the physiological basis for niche restriction in the zoonotic bacterial obligate intracellular parasite and Q fever agent Coxiella burnetii are characterized. Additionally, these factors are reviewed in the context of C. burnetii evolution and continued (patho) adaptation. C. burnetii replication was strictly dependent on a combination of moderately acidic pH, reduced oxygen tension, and presence of carbon dioxide. Of macronutrients, amino acids alone support replication under physicochemically favorable conditions. In addition to utilizing gluconeogenic substrates for replication, C. burnetii can also utilize glucose to generate biomass. A mutant with a disruption in the gene pckA, encoding phosphoenolpyruvate carboxykinase (PEPCK), the first committed step in gluconeogenesis, could be complemented chemically by the addition of glucose. Disruption of pckA resulted in a moderate glucose-dependent growth defect during infection of cultured host cells. Although, C. burnetii has the theoretical capacity to synthesize essential core metabolites via glycolysis and gluconeogenesis, amino acid auxotrophy essentially restricts C. burnetii replication to a niche providing ample access to amino acids. Overall, the described combination of physiochemical and nutritional growth requirements are strong indicators for why C. burnetii favors an acidified phagolysosome-derived vacuole in respiring tissue for replication.
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Affiliation(s)
| | | | | | - Anders Omsland
- Paul G. Allen School for Global Animal Health, College of Veterinary Medicine, Washington State UniversityPullman, WA, United States
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18
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Miller GBS, Uggerud E. Dissociation of Mg(ii) and Zn(ii) complexes of simple 2-oxocarboxylates – relationship to CO2fixation, and the Grignard and Barbier reactions. Org Biomol Chem 2017; 15:6813-6825. [DOI: 10.1039/c7ob01327b] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The glyoxylate and pyruvate carboxylates have been complexed to Mg(ii) and Zn(ii) to investigate the intrinsic interactions of these important biochemical species in the gas phase.
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Affiliation(s)
- Glenn B. S. Miller
- Mass Spectrometry Laboratory and Centre of Theoretical and Computational Chemistry
- Department of Chemistry
- University of Oslo
- N-0315 Oslo
- Norway
| | - Einar Uggerud
- Mass Spectrometry Laboratory and Centre of Theoretical and Computational Chemistry
- Department of Chemistry
- University of Oslo
- N-0315 Oslo
- Norway
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19
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Abstract
Pyruvate carboxylase is a metabolic enzyme that fuels the tricarboxylic acid cycle with one of its intermediates and also participates in the first step of gluconeogenesis. This large enzyme is multifunctional, and each subunit contains two active sites that catalyze two consecutive reactions that lead to the carboxylation of pyruvate into oxaloacetate, and a binding site for acetyl-CoA, an allosteric regulator of the enzyme. Pyruvate carboxylase oligomers arrange in tetramers and covalently attached biotins mediate the transfer of carboxyl groups between distant active sites. In this chapter, some of the recent findings on pyruvate carboxylase functioning are presented, with special focus on the structural studies of the full length enzyme. The emerging picture reveals large movements of domains that even change the overall quaternary organization of pyruvate carboxylase tetramers during catalysis.
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Affiliation(s)
- Mikel Valle
- Structural Biology Unit, Center for Cooperative Research in Biosciences, CIC bioGUNE, 48160, Derio, Spain.
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20
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Shi J, Cao X, Chen Y, Cronan JE, Guo Z. An Atypical α/β-Hydrolase Fold Revealed in the Crystal Structure of Pimeloyl-Acyl Carrier Protein Methyl Esterase BioG from Haemophilus influenzae. Biochemistry 2016; 55:6705-6717. [PMID: 27933801 DOI: 10.1021/acs.biochem.6b00818] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Pimeloyl-acyl carrier protein (ACP) methyl esterase is an α/β-hydrolase that catalyzes the last biosynthetic step of pimeloyl-ACP, a key intermediate in biotin biosynthesis. Intriguingly, multiple nonhomologous isofunctional forms of this enzyme that lack significant sequence identity are present in diverse bacteria. One such esterase, Escherichia coli BioH, has been shown to be a typical α/β-hydrolase fold enzyme. To gain further insights into the role of this step in biotin biosynthesis, we have determined the crystal structure of another widely distributed pimeloyl-ACP methyl esterase, Haemophilus influenzae BioG, at 1.26 Å. The BioG structure is similar to the BioH structure and is composed of an α-helical lid domain and a core domain that contains a central seven-stranded β-pleated sheet. However, four of the six α-helices that flank both sides of the BioH core β-sheet are replaced with long loops in BioG, thus forming an unusual α/β-hydrolase fold. This structural variation results in a significantly decreased thermal stability of the enzyme. Nevertheless, the lid domain and the residues at the lid-core interface are well conserved between BioH and BioG, in which an analogous hydrophobic pocket for pimelate binding as well as similar ionic interactions with the ACP moiety are retained. Biochemical characterization of site-directed mutants of the residues hypothesized to interact with the ACP moiety supports a similar substrate interaction mode for the two enzymes. Consequently, these enzymes package the identical catalytic function under a considerably different protein surface.
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Affiliation(s)
- Jie Shi
- Department of Chemistry and State Key Lab for Molecular Neuroscience, The Hong Kong University of Science and Technology , Clear Water Bay, Kowloon, Hong Kong SAR, China
| | | | - Yaozong Chen
- Department of Chemistry and State Key Lab for Molecular Neuroscience, The Hong Kong University of Science and Technology , Clear Water Bay, Kowloon, Hong Kong SAR, China
| | | | - Zhihong Guo
- Department of Chemistry and State Key Lab for Molecular Neuroscience, The Hong Kong University of Science and Technology , Clear Water Bay, Kowloon, Hong Kong SAR, China
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21
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Hagmann A, Hunkeler M, Stuttfeld E, Maier T. Hybrid Structure of a Dynamic Single-Chain Carboxylase from Deinococcus radiodurans. Structure 2016; 24:1227-1236. [DOI: 10.1016/j.str.2016.06.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Revised: 05/04/2016] [Accepted: 06/02/2016] [Indexed: 11/28/2022]
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22
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A Biotin Biosynthesis Gene Restricted to Helicobacter. Sci Rep 2016; 6:21162. [PMID: 26868423 PMCID: PMC4751477 DOI: 10.1038/srep21162] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Accepted: 01/12/2016] [Indexed: 02/07/2023] Open
Abstract
In most bacteria the last step in synthesis of the pimelate moiety of biotin is cleavage of the ester bond of pimeloyl-acyl carrier protein (ACP) methyl ester. The paradigm cleavage enzyme is Escherichia coli BioH which together with the BioC methyltransferase allows synthesis of the pimelate moiety by a modified fatty acid biosynthetic pathway. Analyses of the extant bacterial genomes showed that bioH is absent from many bioC-containing bacteria and is replaced by other genes. Helicobacter pylori lacks a gene encoding a homologue of the known pimeloyl-ACP methyl ester cleavage enzymes suggesting that it encodes a novel enzyme that cleaves this intermediate. We isolated the H. pylori gene encoding this enzyme, bioV, by complementation of an E. coli bioH deletion strain. Purified BioV cleaved the physiological substrate, pimeloyl-ACP methyl ester to pimeloyl-ACP by use of a catalytic triad, each member of which was essential for activity. The role of BioV in biotin biosynthesis was demonstrated using a reconstituted in vitro desthiobiotin synthesis system. BioV homologues seem the sole pimeloyl-ACP methyl ester esterase present in the Helicobacter species and their occurrence only in H. pylori and close relatives provide a target for development of drugs to specifically treat Helicobacter infections.
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23
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Abstract
The pathways in Escherichia coli and (largely by analogy) S. enterica remain the paradigm of bacterial lipid synthetic pathways, although recently considerable diversity among bacteria in the specific areas of lipid synthesis has been demonstrated. The structural biology of the fatty acid synthetic proteins is essentially complete. However, the membrane-bound enzymes of phospholipid synthesis remain recalcitrant to structural analyses. Recent advances in genetic technology have allowed the essentialgenes of lipid synthesis to be tested with rigor, and as expected most genes are essential under standard growth conditions. Conditionally lethal mutants are available in numerous genes, which facilitates physiological analyses. The array of genetic constructs facilitates analysis of the functions of genes from other organisms. Advances in mass spectroscopy have allowed very accurate and detailed analyses of lipid compositions as well as detection of the interactions of lipid biosynthetic proteins with one another and with proteins outside the lipid pathway. The combination of these advances has resulted in use of E. coli and S. enterica for discovery of new antimicrobials targeted to lipid synthesis and in deciphering the molecular actions of known antimicrobials. Finally,roles for bacterial fatty acids other than as membrane lipid structural components have been uncovered. For example, fatty acid synthesis plays major roles in the synthesis of the essential enzyme cofactors, biotin and lipoic acid. Although other roles for bacterial fatty acids, such as synthesis of acyl-homoserine quorum-sensing molecules, are not native to E. coli introduction of the relevant gene(s) synthesis of these foreign molecules readily proceeds and the sophisticated tools available can used to decipher the mechanisms of synthesis of these molecules.
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24
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Fraschetti C, Filippi A, Guarcini L, Steinmetz V, Speranza M. Structure and conformation of protonated D-(+)-biotin in the unsolvated state. J Phys Chem B 2015; 119:6198-203. [PMID: 25938640 DOI: 10.1021/acs.jpcb.5b02660] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A combined computational and infrared multiphoton dissociation (IRMPD) spectroscopic investigation shows that protonated d-(+)-biotin, formed in the gas phase by ESI-MS, acquires a folded structure with proton bonding between the ureido and valeryl carbonyls, and that only a single conformer of such a structure predominates. A uniform frequency vs distance correlation function is proposed for the O(+)-H···O and N-H···O bonds involved in the folded conformers of O2'-protonated d-(+)-biotin in the gas phase which, therefore, depends exclusively on the corresponding geometric parameters.
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Affiliation(s)
- Caterina Fraschetti
- †Dipartimento di Chimica e Tecnologie del Farmaco, Università "La Sapienza", Roma, Italy
| | - Antonello Filippi
- †Dipartimento di Chimica e Tecnologie del Farmaco, Università "La Sapienza", Roma, Italy
| | - Laura Guarcini
- †Dipartimento di Chimica e Tecnologie del Farmaco, Università "La Sapienza", Roma, Italy
| | - Vincent Steinmetz
- ‡Laboratoire Chimie Physique, UMR8000 CNRS, Université Paris Sud 11, Orsay, France
| | - Maurizio Speranza
- †Dipartimento di Chimica e Tecnologie del Farmaco, Università "La Sapienza", Roma, Italy
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25
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Sheng X, Liu Y. QM/MM Study of the Reaction Mechanism of the Carboxyl Transferase Domain of Pyruvate Carboxylase from Staphylococcus aureus. Biochemistry 2014; 53:4455-66. [DOI: 10.1021/bi500020r] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Xiang Sheng
- School
of Chemistry and Chemical Engineering, Shandong University, Jinan, Shandong 250100, China
| | - Yongjun Liu
- School
of Chemistry and Chemical Engineering, Shandong University, Jinan, Shandong 250100, China
- Northwest
Institute of Plateau Biology, Chinese Academy of Sciences, Xining, Qinghai 810001, China
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26
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Lasso G, Yu LPC, Gil D, Lázaro M, Tong L, Valle M. Functional conformations for pyruvate carboxylase during catalysis explored by cryoelectron microscopy. Structure 2014; 22:911-22. [PMID: 24882745 DOI: 10.1016/j.str.2014.04.011] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Revised: 04/20/2014] [Accepted: 04/24/2014] [Indexed: 01/15/2023]
Abstract
The tetrameric enzyme pyruvate carboxylase (PC), a biotin-dependent carboxylase, produces oxaloacetate by two consecutive reactions that take place in distant active sites. Previous crystal structures revealed two different configurations for PC tetramers, the so-called symmetric and asymmetric, which were understood as characteristic molecular architectures for PC from different organisms. We have analyzed PC samples from Staphylococcus aureus while the enzyme generates oxaloacetate, expecting PC tetramers to display the conformational landscape relevant for its functioning. Using cryoelectron microscopy (cryo-EM) and sorting techniques, we detect previously defined symmetric and asymmetric architectures, demonstrating that PC maps both arrangements by large conformational changes. Furthermore, we observe that each configuration is coupled to one of the two consecutive enzymatic reactions. The findings describe the structural transitions relevant for the allosteric control of the multifunctional PC and demonstrate that by cryo-EM and classification, we can characterize freely working macromolecules.
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Affiliation(s)
- Gorka Lasso
- Structural Biology Unit, Center for Cooperative Research in Biosciences, CIC bioGUNE, 48160 Derio, Spain
| | - Linda P C Yu
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA
| | - David Gil
- Structural Biology Unit, Center for Cooperative Research in Biosciences, CIC bioGUNE, 48160 Derio, Spain
| | - Melisa Lázaro
- Structural Biology Unit, Center for Cooperative Research in Biosciences, CIC bioGUNE, 48160 Derio, Spain
| | - Liang Tong
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA
| | - Mikel Valle
- Structural Biology Unit, Center for Cooperative Research in Biosciences, CIC bioGUNE, 48160 Derio, Spain; Department of Biochemistry and Molecular Biology, University of the Basque Country, P.O. Box 644, 48080 Bilbao, Spain.
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27
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Adina-Zada A, Jitrapakdee S, Wallace JC, Attwood PV. Coordinating role of His216 in MgATP binding and cleavage in pyruvate carboxylase. Biochemistry 2014; 53:1051-8. [PMID: 24460480 PMCID: PMC3985934 DOI: 10.1021/bi4016814] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
![]()
His216
is a well-conserved residue in pyruvate carboxylases and,
on the basis of structures of the enzyme, appears to have a role in
the binding of MgATP, forming an interaction with the 3′-hydroxyl
group of the ribose ring. Mutation of this residue to asparagine results
in a 9-fold increase in the Km for MgATP
in its steady-state cleavage in the absence of pyruvate and a 3-fold
increase in the Km for MgADP in its steady-state
phosphorylation by carbamoyl phosphate. However, from single-turnover
experiments of MgATP cleavage, the Kd of
the enzyme·MgATP complex is essentially the same in the wild-type
enzyme and H216N. Direct stopped-flow measurements of nucleotide binding
and release using the fluorescent analogue FTP support these observations.
However, the first-order rate constant for MgATP cleavage in the single-turnover
experiments in H216N is only 0.75% of that for the wild-type enzyme,
and thus, the MgATP cleavage step is rate-limiting in the steady state
for H216N but not for the wild-type enzyme. Close examination of the
structure of the enzyme suggested that His216 may also interact with
Glu218, which in turn interacts with Glu305 to form a proton relay
system involved in the deprotonation of bicarbonate. Single-turnover
MgATP cleavage experiments with mutations of these two residues resulted
in kinetic parameters similar to those observed in H216N. We suggest
that the primary role of His216 is to coordinate the binding of MgATP
and the deprotonation of bicarbonate in the reaction to form the putative
carboxyphosphate intermediate by participation in a proton relay system
involving Glu218 and Glu305.
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Affiliation(s)
- Abdussalam Adina-Zada
- School of Chemistry and Biochemistry, The University of Western Australia , 35 Stirling Highway, Crawley, WA 6009, Australia
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28
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Feng Y, Napier BA, Manandhar M, Henke SK, Weiss DS, Cronan JE. A Francisella virulence factor catalyses an essential reaction of biotin synthesis. Mol Microbiol 2013; 91:300-14. [PMID: 24313380 DOI: 10.1111/mmi.12460] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/12/2013] [Indexed: 01/09/2023]
Abstract
We recently identified a gene (FTN_0818) required for Francisella virulence that seemed likely involved in biotin metabolism. However, the molecular function of this virulence determinant was unclear. Here we show that this protein named BioJ is the enzyme of the biotin biosynthesis pathway that determines the chain length of the biotin valeryl side-chain. Expression of bioJ allows growth of an Escherichia coli bioH strain on biotin-free medium, indicating functional equivalence of BioJ to the paradigm pimeloyl-ACP methyl ester carboxyl-esterase, BioH. BioJ was purified to homogeneity, shown to be monomeric and capable of hydrolysis of its physiological substrate methyl pimeloyl-ACP to pimeloyl-ACP, the precursor required to begin formation of the fused heterocyclic rings of biotin. Phylogenetic analyses confirmed that distinct from BioH, BioJ represents a novel subclade of the α/β-hydrolase family. Structure-guided mapping combined with site-directed mutagenesis revealed that the BioJ catalytic triad consists of Ser151, Asp248 and His278, all of which are essential for activity and virulence. The biotin synthesis pathway was reconstituted reaction in vitro and the physiological role of BioJ directly assayed. To the best of our knowledge, these data represent further evidence linking biotin synthesis to bacterial virulence.
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Affiliation(s)
- Youjun Feng
- Department of Microbiology, University of Illinois at Urbana-Champaign, IL, 61801, USA; Institute of Microbiology, College of Life Science, Zhejiang University, Hangzhou, Zhejiang Province, China
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29
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A small-molecule-linked DNA–graphene oxide-based fluorescence-sensing system for detection of biotin. Anal Biochem 2013; 442:172-7. [DOI: 10.1016/j.ab.2013.07.036] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Revised: 07/14/2013] [Accepted: 07/26/2013] [Indexed: 12/19/2022]
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30
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Dewal MB, Firestine SM. Site-directed mutagenesis of catalytic residues in N(5)-carboxyaminoimidazole ribonucleotide synthetase. Biochemistry 2013; 52:6559-67. [PMID: 23899325 DOI: 10.1021/bi400444y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
N(5)-CAIR synthetase, an essential enzyme in microorganisms, converts 5-aminoimidazole ribonucleotide (AIR) and bicarbonate to N(5)-CAIR with the aid of ATP. Previous X-ray crystallographic analyses of Aspergillus clavatus N(5)-CAIR synthetase postulated that R271, H273, and K353 were important for bicarbonate binding and for catalysis. As reported here, site-directed mutagenesis of these residues revealed that R271 and H273 are, indeed, critical for bicarbonate binding and catalysis whereas all K353 mutations, even ones conservative in nature, are inactive. Studies on the R271K mutant protein revealed cooperative substrate inhibition for ATP with a Ki of 1.2 mM. Kinetic investigation of the H273A mutant protein indicated that it was cooperative with respect to AIR; however, this effect was not seen in either the wild-type or any of the other mutant proteins. Cooperative ATP-dependent inhibition of wild-type N(5)-CAIR synthetase was also detected with ATP displaying a Ki of 3.3 mM. Taken together, these results indicate that N(5)-CAIR synthetase operates maximally within a narrow concentration of ATP.
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Affiliation(s)
- Mahender B Dewal
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, Michigan 48201, United States
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31
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Arpornsuwan T, Carey KJ, Booker GW, Polyak SW, Wallace JC. Localization of inhibitory antibodies to the biotin domain of human pyruvate carboxylase. Hybridoma (Larchmt) 2013; 31:305-13. [PMID: 23098296 DOI: 10.1089/hyb.2012.0044] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Pyruvate carboxylase [EC 6.4.1.1] plays an important anaplerotic role in many species by catalyzing the carboxylation of pyruvate to oxaloacetate. To extend our understanding about the structure and function of pyruvate carboxylase (PC), a series of monoclonal antibodies were raised against sheep liver PC and those displaying inhibitory activity were further characterized. The binding epitopes of two monoclonal antibodies that displayed strong inhibitory activity were mapped. Six overlapping fragments of the human enzyme were expressed as thioredoxin fusion proteins in Escherichia coli and subjected to Western blot analysis. Both monoclonal antibodies (MAbs) recognized fragments encompassing the enzyme's C-terminal region, known to contain the structured biotin domain. Through deletion analysis, this domain was determined to be a minimal size of 80 amino acids. Further deletions that disrupted the conformation of the domain abolished antibody binding, indicating these antibodies recognized discontinuous epitopes. To further define the critical residues required for antibody recognition, a model of the domain was produced and an alanine scan performed on selected surface-exposed residues. Our results show that residues encompassing the biotin attachment site, but not biotin itself, are critical for the binding of both antibodies. These data provide a mechanism to explain the inhibitory activity of the antibodies.
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Affiliation(s)
- Teerakul Arpornsuwan
- The School of Molecular and Biomedical Sciences, The University of Adelaide, North Terrace, Adelaide, South Australia
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32
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Lommel K, Schäfer G, Grenader K, Ruland C, Terfort A, Mäntele W, Wille G. Caged CO2for the Direct Observation of CO2-Consuming Reactions. Chembiochem 2013; 14:372-80. [DOI: 10.1002/cbic.201200659] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2012] [Indexed: 11/07/2022]
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33
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Avoiding CO2 in Catalysis of Decarboxylation. ADVANCES IN PHYSICAL ORGANIC CHEMISTRY 2013. [DOI: 10.1016/b978-0-12-407754-6.00002-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register]
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34
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Remarkable diversity in the enzymes catalyzing the last step in synthesis of the pimelate moiety of biotin. PLoS One 2012; 7:e49440. [PMID: 23152908 PMCID: PMC3494674 DOI: 10.1371/journal.pone.0049440] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2012] [Accepted: 10/09/2012] [Indexed: 12/13/2022] Open
Abstract
Biotin synthesis in Escherichia coli requires the functions of the bioH and bioC genes to synthesize the precursor pimelate moiety by use of a modified fatty acid biosynthesis pathway. However, it was previously noted that bioH has been replaced with bioG or bioK within the biotin synthetic gene clusters of other bacteria. We report that each of four BioG proteins from diverse bacteria and two cyanobacterial BioK proteins functionally replace E. coli BioH in vivo. Moreover, purified BioG proteins have esterase activity against pimeloyl-ACP methyl ester, the physiological substrate of BioH. Two of the BioG proteins block biotin synthesis when highly expressed and these toxic proteins were shown to have more promiscuous substrate specificities than the non-toxic BioG proteins. A postulated BioG-BioC fusion protein was shown to functionally replace both the BioH and BioC functions of E. coli. Although the BioH, BioG and BioK esterases catalyze a common reaction, the proteins are evolutionarily distinct.
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Adina-Zada A, Sereeruk C, Jitrapakdee S, Zeczycki TN, St Maurice M, Cleland WW, Wallace JC, Attwood PV. Roles of Arg427 and Arg472 in the binding and allosteric effects of acetyl CoA in pyruvate carboxylase. Biochemistry 2012; 51:8208-17. [PMID: 22985389 DOI: 10.1021/bi301060d] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Mutation of Arg427 and Arg472 in Rhizobium etli pyruvate carboxylase to serine or lysine greatly increased the activation constant (K(a)) of acetyl CoA, with the increase being greater for the Arg472 mutants. These results indicate that while both these residues are involved in the binding of acetyl CoA to the enzyme, Arg472 is more important than Arg427. The mutations had substantially smaller effects on the k(cat) for pyruvate carboxylation. Part of the effects of the mutations was to increase the K(m) for MgATP and the K(a) for activation by free Mg(2+) determined at saturating acetyl CoA concentrations. The inhibitory effects of the mutations on the rates of the enzyme-catalyzed bicarbonate-dependent ATP cleavage, carboxylation of biotin, and phosphorylation of ADP by carbamoyl phosphate indicate that the major locus of the effects of the mutations was in the biotin carboxylase (BC) domain active site. Even though both Arg427 and Arg472 are distant from the BC domain active site, it is proposed that their contacts with other residues in the allosteric domain, either directly or through acetyl CoA, affect the positioning and orientation of the biotin-carboxyl carrier protein (BCCP) domain and thus the binding of biotin at the BC domain active site. On the basis of the kinetic analysis proposed here, it is proposed that mutations of Arg427 and Arg472 perturb these contacts and consequently the binding of biotin at the BC domain active site. Inhibition of pyruvate carboxylation by the allosteric inhibitor l-aspartate was largely unaffected by the mutation of either Arg427 or Arg472.
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Affiliation(s)
- Abdussalam Adina-Zada
- School of Chemistry and Biochemistry, The University of Western Australia, 35 Stirling Highway, Crawley, Western Australia 6009, Australia
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36
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Biotin-binding proteins in the defense of mushrooms against predators and parasites. Appl Environ Microbiol 2012; 78:8485-7. [PMID: 23001676 DOI: 10.1128/aem.02286-12] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Tamavidins are fungal biotin-binding proteins (BBPs) displaying antifungal activity against phytopathogens. Here we show high toxicity of tamavidins toward nematodes, insects, and amoebae. As these organisms represent important phyla of fungal predators and parasites, we propose that BBPs are part of the chemical defense system of fungi.
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37
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Allosteric regulation of the biotin-dependent enzyme pyruvate carboxylase by acetyl-CoA. Biochem Soc Trans 2012; 40:567-72. [PMID: 22616868 DOI: 10.1042/bst20120041] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The activity of the biotin-dependent enzyme pyruvate carboxylase from many organisms is highly regulated by the allosteric activator acetyl-CoA. A number of X-ray crystallographic structures of the native pyruvate carboxylase tetramer are now available for the enzyme from Rhizobium etli and Staphylococcus aureus. Although all of these structures show that intersubunit catalysis occurs, in the case of the R. etli enzyme, only two of the four subunits have the allosteric activator bound to them and are optimally configured for catalysis of the overall reaction. However, it is apparent that acetyl-CoA binding does not induce the observed asymmetrical tetramer conformation and it is likely that, under normal reaction conditions, all of the subunits have acetyl-CoA bound to them. Thus the activation of the enzyme by acetyl-CoA involves more subtle structural effects, one of which may be to facilitate the correct positioning of Arg353 and biotin in the biotin carboxylase domain active site, thereby promoting biotin carboxylation and, at the same time, preventing abortive decarboxylation of carboxybiotin. It is also apparent from the crystal structures that there are allosteric interactions induced by acetyl-CoA binding in the pair of subunits not optimally configured for catalysis of the overall reaction.
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38
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Lin S, Cronan JE. The BioC O-methyltransferase catalyzes methyl esterification of malonyl-acyl carrier protein, an essential step in biotin synthesis. J Biol Chem 2012; 287:37010-20. [PMID: 22965231 DOI: 10.1074/jbc.m112.410290] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Recent work implicated the Escherichia coli BioC protein as the initiator of the synthetic pathway that forms the pimeloyl moiety of biotin (Lin, S., Hanson, R. E., and Cronan, J. E. (2010) Nat. Chem. Biol. 6, 682-688). BioC was believed to be an O-methyltransferase that methylated the free carboxyl of either malonyl-CoA or malonyl-acyl carrier protein based on the ability of O-methylated (but not unmethylated) precursors to bypass the BioC requirement for biotin synthesis both in vivo and in vitro. However, only indirect proof of the hypothesized enzymatic activity was obtained because the activities of the available BioC preparations were too low for direct enzymatic assay. Because E. coli BioC protein was extremely recalcitrant to purification in an active form, BioC homologues of other bacteria were tested. We report that the native form of Bacillus cereus ATCC10987 BioC functionally replaced E. coli BioC in vivo, and the protein could be expressed in soluble form and purified to homogeneity. In disagreement with prior scenarios that favored malonyl-CoA as the methyl acceptor, malonyl-acyl carrier protein was a far better acceptor of methyl groups from S-adenosyl-L-methionine than was malonyl-CoA. BioC was specific for the malonyl moiety and was inhibited by S-adenosyl-L-homocysteine and sinefungin. High level expression of B. cereus BioC in E. coli blocked cell growth and fatty acid synthesis.
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Affiliation(s)
- Steven Lin
- Department of Microbiology, University of Illinois, Urbana, Illinois 61801, USA
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39
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Structure and function of biotin-dependent carboxylases. Cell Mol Life Sci 2012; 70:863-91. [PMID: 22869039 DOI: 10.1007/s00018-012-1096-0] [Citation(s) in RCA: 254] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2012] [Revised: 07/07/2012] [Accepted: 07/09/2012] [Indexed: 12/14/2022]
Abstract
Biotin-dependent carboxylases include acetyl-CoA carboxylase (ACC), propionyl-CoA carboxylase (PCC), 3-methylcrotonyl-CoA carboxylase (MCC), geranyl-CoA carboxylase, pyruvate carboxylase (PC), and urea carboxylase (UC). They contain biotin carboxylase (BC), carboxyltransferase (CT), and biotin-carboxyl carrier protein components. These enzymes are widely distributed in nature and have important functions in fatty acid metabolism, amino acid metabolism, carbohydrate metabolism, polyketide biosynthesis, urea utilization, and other cellular processes. ACCs are also attractive targets for drug discovery against type 2 diabetes, obesity, cancer, microbial infections, and other diseases, and the plastid ACC of grasses is the target of action of three classes of commercial herbicides. Deficiencies in the activities of PCC, MCC, or PC are linked to serious diseases in humans. Our understanding of these enzymes has been greatly enhanced over the past few years by the crystal structures of the holoenzymes of PCC, MCC, PC, and UC. The structures reveal unanticipated features in the architectures of the holoenzymes, including the presence of previously unrecognized domains, and provide a molecular basis for understanding their catalytic mechanism as well as the large collection of disease-causing mutations in PCC, MCC, and PC. This review will summarize the recent advances in our knowledge on the structure and function of these important metabolic enzymes.
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40
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Li T, Huo L, Pulley C, Liu A. Decarboxylation mechanisms in biological system. Bioorg Chem 2012; 43:2-14. [PMID: 22534166 DOI: 10.1016/j.bioorg.2012.03.001] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2011] [Revised: 03/04/2012] [Accepted: 03/19/2012] [Indexed: 11/30/2022]
Abstract
This review examines the mechanisms propelling cofactor-independent, organic cofactor-dependent and metal-dependent decarboxylase chemistry. Decarboxylation, the removal of carbon dioxide from organic acids, is a fundamentally important reaction in biology. Numerous decarboxylase enzymes serve as key components of aerobic and anaerobic carbohydrate metabolism and amino acid conversion. In the past decade, our knowledge of the mechanisms enabling these crucial decarboxylase reactions has continued to expand and inspire. This review focuses on the organic cofactors biotin, flavin, NAD, pyridoxal 5'-phosphate, pyruvoyl, and thiamin pyrophosphate as catalytic centers. Significant attention is also placed on the metal-dependent decarboxylase mechanisms.
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Affiliation(s)
- Tingfeng Li
- Department of Biochemistry, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS 39216, USA
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41
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Fan C, Chou CY, Tong L, Xiang S. Crystal structure of urea carboxylase provides insights into the carboxyltransfer reaction. J Biol Chem 2012; 287:9389-98. [PMID: 22277658 DOI: 10.1074/jbc.m111.319475] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Urea carboxylase (UC) is conserved in many bacteria, algae, and fungi and catalyzes the conversion of urea to allophanate, an essential step in the utilization of urea as a nitrogen source in these organisms. UC belongs to the biotin-dependent carboxylase superfamily and shares the biotin carboxylase (BC) and biotin carboxyl carrier protein (BCCP) domains with these other enzymes, but its carboxyltransferase (CT) domain is distinct. Currently, there is no information on the molecular basis of catalysis by UC. We report here the crystal structure of the Kluyveromyces lactis UC and biochemical studies to assess the structural information. Structural and sequence analyses indicate the CT domain of UC belongs to a large family of proteins with diverse functions, including the Bacillus subtilis KipA-KipI complex, which has important functions in sporulation regulation. A structure of the KipA-KipI complex is not currently available, and our structure provides a framework to understand the function of this complex. Most interestingly, in the structure the CT domain interacts with the BCCP domain, with biotin and a urea molecule bound at its active site. This structural information and our follow-up biochemical experiments provided molecular insights into the UC carboxyltransfer reaction. Several structural elements important for the UC carboxyltransfer reaction are found in other biotin-dependent carboxylases and might be conserved within this family, and our data could shed light on the mechanism of catalysis of these enzymes.
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Affiliation(s)
- Chen Fan
- Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
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42
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Fawaz MV, Topper M, Firestine SM. The ATP-grasp enzymes. Bioorg Chem 2011; 39:185-91. [PMID: 21920581 PMCID: PMC3243065 DOI: 10.1016/j.bioorg.2011.08.004] [Citation(s) in RCA: 130] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2011] [Revised: 08/12/2011] [Accepted: 08/13/2011] [Indexed: 12/17/2022]
Abstract
The ATP-grasp enzymes consist of a superfamily of 21 proteins that contain an atypical ATP-binding site, called the ATP-grasp fold. The ATP-grasp fold is comprised of two α+β domains that "grasp" a molecule of ATP between them and members of the family typically have an overall structural design containing three common conserved focal domains. The founding members of the family consist of biotin carboxylase, d-ala-d-ala ligase and glutathione synthetase, all of which catalyze the ATP-assisted reaction of a carboxylic acid with a nucleophile via the formation of an acylphosphate intermediate. While most members of the superfamily follow this mechanistic pathway, studies have demonstrated that two enzymes catalyze only the phosphoryl transfer step and thus are kinases instead of ligases. Members of the ATP-grasp superfamily are found in several metabolic pathways including de novo purine biosynthesis, gluconeogenesis, and fatty acid synthesis. Given the critical nature of these enzymes, researchers have actively sought the development of potent inhibitors of several members of the superfamily as antibacterial and anti-obseity agents. In this review, we will discuss the structure, function, mechanism, and inhibition of the ATP-grasp enzymes.
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Affiliation(s)
| | | | - Steven M. Firestine
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, MI 48201
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43
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Affiliation(s)
- Ashok D. Pehere
- School of Chemistry & Physics, The University of Adelaide, North Terrace, Adelaide SA 5005, Australia
| | - Andrew D. Abell
- School of Chemistry & Physics, The University of Adelaide, North Terrace, Adelaide SA 5005, Australia
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44
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Zeczycki TN, Menefee AL, Adina-Zada A, Jitrapakdee S, Surinya KH, Wallace JC, Attwood PV, St. Maurice M, Cleland WW. Novel insights into the biotin carboxylase domain reactions of pyruvate carboxylase from Rhizobium etli. Biochemistry 2011; 50:9724-37. [PMID: 21957995 PMCID: PMC3211089 DOI: 10.1021/bi2012788] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
The catalytic mechanism of the MgATP-dependent carboxylation of biotin in the biotin carboxylase domain of pyruvate carboxylase from R. etli (RePC) is common to the biotin-dependent carboxylases. The current site-directed mutagenesis study has clarified the catalytic functions of several residues proposed to be pivotal in MgATP-binding and cleavage (Glu218 and Lys245), HCO(3)(-) deprotonation (Glu305 and Arg301), and biotin enolization (Arg353). The E218A mutant was inactive for any reaction involving the BC domain and the E218Q mutant exhibited a 75-fold decrease in k(cat) for both pyruvate carboxylation and the full reverse reaction. The E305A mutant also showed a 75- and 80-fold decrease in k(cat) for both pyruvate carboxylation and the full reverse reaction, respectively. While Glu305 appears to be the active site base which deprotonates HCO(3)(-), Lys245, Glu218, and Arg301 are proposed to contribute to catalysis through substrate binding interactions. The reactions of the biotin carboxylase and carboxyl transferase domains were uncoupled in the R353M-catalyzed reactions, indicating that Arg353 may not only facilitate the formation of the biotin enolate but also assist in coordinating catalysis between the two spatially distinct active sites. The 2.5- and 4-fold increase in k(cat) for the full reverse reaction with the R353K and R353M mutants, respectively, suggests that mutation of Arg353 allows carboxybiotin increased access to the biotin carboxylase domain active site. The proposed chemical mechanism is initiated by the deprotonation of HCO(3)(-) by Glu305 and concurrent nucleophilic attack on the γ-phosphate of MgATP. The trianionic carboxyphosphate intermediate formed reversibly decomposes in the active site to CO(2) and PO(4)(3-). PO(4)(3-) then acts as the base to deprotonate the tethered biotin at the N(1)-position. Stabilized by interactions between the ureido oxygen and Arg353, the biotin-enolate reacts with CO(2) to give carboxybiotin. The formation of a distinct salt bridge between Arg353 and Glu248 is proposed to aid in partially precluding carboxybiotin from reentering the biotin carboxylase active site, thus preventing its premature decarboxylation prior to the binding of a carboxyl acceptor in the carboxyl transferase domain.
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Affiliation(s)
- Tonya N. Zeczycki
- Institute for Enzyme Research and Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53726
| | - Ann L. Menefee
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin 53201
| | - Abdussalam Adina-Zada
- School of Biomedical, Biomolecular and Chemical Sciences, University of Western Australia, Crawley WA, 6009 Australia
| | - Sarawut Jitrapakdee
- Department of Biochemistry, Faculty of Science, Mahidol University, Bangkok 10400, Thailand
| | - Kathy H. Surinya
- School of Molecular and Biomedical Science, University of Adelaide, Adelaide S.A., 5005, Australia
| | - John C. Wallace
- School of Molecular and Biomedical Science, University of Adelaide, Adelaide S.A., 5005, Australia
| | - Paul V. Attwood
- School of Biomedical, Biomolecular and Chemical Sciences, University of Western Australia, Crawley WA, 6009 Australia
| | - Martin St. Maurice
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin 53201
| | - W. Wallace Cleland
- Institute for Enzyme Research and Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53726
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Zeczycki TN, Menefee AL, Jitrapakdee S, Wallace JC, Attwood PV, St Maurice M, Cleland WW. Activation and inhibition of pyruvate carboxylase from Rhizobium etli. Biochemistry 2011; 50:9694-707. [PMID: 21958066 DOI: 10.1021/bi201276r] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
While crystallographic structures of the R. etli pyruvate carboxylase (PC) holoenzyme revealed the location and probable positioning of the essential activator, Mg(2+), and nonessential activator, acetyl-CoA, an understanding of how they affect catalysis remains unclear. The current steady-state kinetic investigation indicates that both acetyl-CoA and Mg(2+) assist in coupling the MgATP-dependent carboxylation of biotin in the biotin carboxylase (BC) domain with pyruvate carboxylation in the carboxyl transferase (CT) domain. Initial velocity plots of free Mg(2+) vs pyruvate were nonlinear at low concentrations of Mg(2+) and a nearly complete loss of coupling between the BC and CT domain reactions was observed in the absence of acetyl-CoA. Increasing concentrations of free Mg(2+) also resulted in a decrease in the K(a) for acetyl-CoA. Acetyl phosphate was determined to be a suitable phosphoryl donor for the catalytic phosphorylation of MgADP, while phosphonoacetate inhibited both the phosphorylation of MgADP by carbamoyl phosphate (K(i) = 0.026 mM) and pyruvate carboxylation (K(i) = 2.5 mM). In conjunction with crystal structures of T882A R. etli PC mutant cocrystallized with phosphonoacetate and MgADP, computational docking studies suggest that phosphonoacetate could coordinate to one of two Mg(2+) metal centers in the BC domain active site. Based on the pH profiles, inhibition studies, and initial velocity patterns, possible mechanisms for the activation, regulation, and coordination of catalysis between the two spatially distinct active sites in pyruvate carboxylase from R. etli by acetyl-CoA and Mg(2+) are described.
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Affiliation(s)
- Tonya N Zeczycki
- Institute for Enzyme Research and Department of Biochemistry, University of Wisconsin, Madison, Wisconsin 53726, United States
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46
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A novel molecular mechanism to explain biotin-unresponsive holocarboxylase synthetase deficiency. J Mol Med (Berl) 2011; 90:81-8. [DOI: 10.1007/s00109-011-0811-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2011] [Revised: 07/26/2011] [Accepted: 08/18/2011] [Indexed: 10/17/2022]
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47
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Proteomics of early and late cold shock stress on thermophilic bacterium, Thermus sp. GH5. J Proteomics 2011; 74:2100-11. [DOI: 10.1016/j.jprot.2011.05.037] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2010] [Revised: 05/18/2011] [Accepted: 05/25/2011] [Indexed: 11/19/2022]
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48
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Lin S, Cronan JE. Closing in on complete pathways of biotin biosynthesis. MOLECULAR BIOSYSTEMS 2011; 7:1811-21. [PMID: 21437340 DOI: 10.1039/c1mb05022b] [Citation(s) in RCA: 104] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Biotin is an enzyme cofactor indispensable to metabolic fixation of carbon dioxide in all three domains of life. Although the catalytic and physiological roles of biotin have been well characterized, the biosynthesis of biotin remains to be fully elucidated. Studies in microbes suggest a two-stage biosynthetic pathway in which a pimelate moiety is synthesized and used to begin assembly of the biotin bicyclic ring structure. The enzymes involved in the bicyclic ring assembly have been studied extensively. In contrast the synthesis of pimelate, a seven carbon α,ω-dicarboxylate, has long been an enigma. Support for two different routes of pimelate synthesis has recently been obtained in Escherichia coli and Bacillus subtilis. The E. coli BioC-BioH pathway employs a methylation and demethylation strategy to allow elongation of a temporarily disguised malonate moiety to a pimelate moiety by the fatty acid synthetic enzymes whereas the B. subtilis BioI-BioW pathway utilizes oxidative cleavage of fatty acyl chains. Both pathways produce the pimelate thioester precursor essential for the first step in assembly of the fused rings of biotin. The enzymatic mechanisms and biochemical strategies of these pimelate synthesis models will be discussed in this review.
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Affiliation(s)
- Steven Lin
- Department of Microbiology, University of Illinois, B103 Chemical and Life Sciences Laboratory, 601 S. Goodwin Ave, Urbana, Illinois 61801, USA
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49
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Kimura H, Young CR, Martinez A, Delong EF. Light-induced transcriptional responses associated with proteorhodopsin-enhanced growth in a marine flavobacterium. ISME JOURNAL 2011; 5:1641-51. [PMID: 21472017 DOI: 10.1038/ismej.2011.36] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Proteorhodopsin (PR) is a photoprotein that functions as a light-driven proton pump in diverse marine Bacteria and Archaea. Recent studies have suggested that PR may enhance both growth rate and yield in some flavobacteria when grown under nutrient-limiting conditions in the light. The direct involvement of PR, and the metabolic details enabling light-stimulated growth, however, remain uncertain. Here, we surveyed transcriptional and growth responses of a PR-containing marine flavobacterium during carbon-limited growth in the light and the dark. As previously reported (Gómez-Consarnau et al., 2007), Dokdonia strain MED134 exhibited light-enhanced growth rates and cell yields under low carbon growth conditions. Inhibition of retinal biosynthesis abolished the light-stimulated growth response, supporting a direct role for retinal-bound PR in light-enhanced growth. Among protein-coding transcripts, both PR and retinal biosynthetic enzymes showed significant upregulation in the light. Other light-associated proteins, including bacterial cryptochrome and DNA photolyase, were also expressed at significantly higher levels in the light. Membrane transporters for Na(+)/phosphate and Na(+)/alanine symporters, and the Na(+)-translocating NADH-quinone oxidoreductase (NQR) linked electron transport chain, were also significantly upregulated in the light. Culture experiments using a specific inhibitor of Na(+)-translocating NQR indicated that sodium pumping via NQR is a critical metabolic process in the light-stimulated growth of MED134. In total, the results suggested the importance of both the PR-enabled, light-driven proton gradient, as well as the generation of a Na(+) ion gradient, as essential components for light-enhanced growth in these flavobacteria.
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Affiliation(s)
- Hiroyuki Kimura
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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50
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Probing the allosteric activation of pyruvate carboxylase using 2',3'-O-(2,4,6-trinitrophenyl) adenosine 5'-triphosphate as a fluorescent mimic of the allosteric activator acetyl CoA. Arch Biochem Biophys 2011; 509:117-26. [PMID: 21426897 DOI: 10.1016/j.abb.2011.03.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2010] [Revised: 03/12/2011] [Accepted: 03/13/2011] [Indexed: 01/15/2023]
Abstract
2',3'-O-(2,4,6-Trinitrophenyl) adenosine 5'-triphosphate (TNP-ATP) is a fluorescent analogue of ATP. MgTNP-ATP was found to be an allosteric activator of pyruvate carboxylase that exhibits competition with acetyl CoA in activating the enzyme. There is no evidence that MgTNP-ATP binds to the MgATP substrate binding site of the enzyme. At concentrations above saturating, MgATP activates bicarbonate-dependent ATP cleavage, but inhibits the overall reaction. The fluorescence of MgTNP-ATP increases by about 2.5-fold upon binding to the enzyme and decreases on addition of saturating acetyl CoA. However, not all the MgTNP-ATP is displaced by acetyl CoA, or with a combination of saturating concentrations of MgATP and acetyl CoA. The kinetics of the binding of MgTNP-ATP to pyruvate carboxylase have been measured and shown to be triphasic, with the two fastest phases having pseudo first-order rate constants that are dependent on the concentration of MgTNP-ATP. The kinetics of displacement from the enzyme by acetyl CoA have been measured and also shown to be triphasic. A model of the binding process is proposed that links the kinetics of MgTNP-ATP binding to the allosteric activation of the enzyme.
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