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Chen X, Wei W, Xiong W, Wu S, Wu Q, Wang P, Zhu G. Two Different Isocitrate Dehydrogenases from Pseudomonas aeruginosa: Enzymology and Coenzyme-Evolutionary Implications. Int J Mol Sci 2023; 24:14985. [PMID: 37834433 PMCID: PMC10574006 DOI: 10.3390/ijms241914985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 10/03/2023] [Accepted: 10/04/2023] [Indexed: 10/15/2023] Open
Abstract
Pseudomonas aeruginosa PAO1, as an experimental model for Gram-negative bacteria, harbors two NADP+-dependent isocitrate dehydrogenases (NADP-IDHs) that were evolved from its ancient counterpart NAD-IDHs. For a better understanding of PaIDH1 and PaIDH2, we cloned the genes, overexpressed them in Escherichia coli and purified them to homogeneity. PaIDH1 displayed higher affinity to NADP+ and isocitrate, with lower Km values when compared to PaIDH2. Moreover, PaIDH1 possessed higher temperature tolerance (50 °C) and wider pH range tolerance (7.2-8.5) and could be phosphorylated. After treatment with the bifunctional PaIDH kinase/phosphatase (PaIDH K/P), PaIDH1 lost 80% of its enzymatic activity in one hour due to the phosphorylation of Ser115. Small-molecule compounds like glyoxylic acid and oxaloacetate can effectively inhibit the activity of PaIDHs. The mutant PaIDH1-D346I347A353K393 exhibited enhanced affinity for NAD+ while it lost activity towards NADP+, and the Km value (7770.67 μM) of the mutant PaIDH2-L589 I600 for NADP+ was higher than that observed for NAD+ (5824.33 μM), indicating a shift in coenzyme specificity from NADP+ to NAD+ for both PaIDHs. The experiments demonstrated that the mutation did not alter the oligomeric state of either protein. This study provides a foundation for the elucidation of the evolution and function of two NADP-IDHs in the pathogenic bacterium P. aeruginosa.
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Affiliation(s)
| | | | | | | | | | - Peng Wang
- Anhui Provincial Key Laboratory of Molecular Enzymology and Mechanism of Major Diseases and Key Laboratory of Biomedicine in Gene Diseases and Health of Anhui Higher Education Institutes, Anhui Normal University, Wuhu 241000, China; (X.C.); (W.W.); (W.X.); (S.W.); (Q.W.)
| | - Guoping Zhu
- Anhui Provincial Key Laboratory of Molecular Enzymology and Mechanism of Major Diseases and Key Laboratory of Biomedicine in Gene Diseases and Health of Anhui Higher Education Institutes, Anhui Normal University, Wuhu 241000, China; (X.C.); (W.W.); (W.X.); (S.W.); (Q.W.)
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Bian M, Zhao J, Xu W, Han X, Chen X, Wang P, Zhu G. Enzymatic Characterization of the Isocitrate Dehydrogenase with Dual Coenzyme Specificity from the Marine Bacterium Umbonibacter marinipuiceus. Int J Mol Sci 2023; 24:11428. [PMID: 37511187 PMCID: PMC10380307 DOI: 10.3390/ijms241411428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 07/07/2023] [Accepted: 07/11/2023] [Indexed: 07/30/2023] Open
Abstract
Isocitrate dehydrogenase (IDH) can be divided into NAD+-dependent and NADP+-dependent types based on the coenzyme specificity. It is worth noting that some IDHs exhibit dual coenzyme specificity characteristics. Herein, a dual coenzyme-dependent IDH from Umbonibacter Marinipuiceus (UmIDH) was expressed, purified, and identified in detail for the first time. SDS-PAGE and Gel filtration chromatography analyses showed that UmIDH is an 84.7 kDa homodimer in solution. The Km values for NAD+ and NADP+ are 1800.0 ± 64.4 μM and 1167.7 ± 113.0 μM in the presence of Mn2+, respectively. Meanwhile, the catalytic efficiency (kcat/Km) of UmIDH is only 2.3-fold greater for NADP+ than NAD+. The maximal activity for UmIDH occurred at pH 8.5 (with Mn2+) or pH 8.7 (with Mg2+) and at 35 °C (with Mn2+ or Mg2+). Heat inactivation assay revealed that UmIDH sustained 50% of maximal activity after incubation at 57 °C for 20 min with either Mn2+ or Mg2+. Moreover, three putative core coenzyme binding residues (R345, L346, and V352) of UmIDH were evaluated by site-directed mutagenesis. This recent work identified a unique dual coenzyme-dependent IDH and achieved the groundbreaking bidirectional modification of this specific IDH's coenzyme dependence for the first time. This provides not only a reference for the study of dual coenzyme-dependent IDH, but also a basis for the investigation of the coenzyme-specific evolutionary mechanisms of IDH.
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Affiliation(s)
- Mingjie Bian
- Anhui Provincial Key Laboratory of Molecular Enzymology and Mechanism of Major Diseases, Key Laboratory of Biomedicine in Gene Diseases and Health of Anhui Higher Education Institutes, Anhui Normal University, Wuhu 241000, China
| | - Jiaxin Zhao
- Anhui Provincial Key Laboratory of Molecular Enzymology and Mechanism of Major Diseases, Key Laboratory of Biomedicine in Gene Diseases and Health of Anhui Higher Education Institutes, Anhui Normal University, Wuhu 241000, China
| | - Wenqiang Xu
- Anhui Provincial Key Laboratory of Molecular Enzymology and Mechanism of Major Diseases, Key Laboratory of Biomedicine in Gene Diseases and Health of Anhui Higher Education Institutes, Anhui Normal University, Wuhu 241000, China
| | - Xueyang Han
- Anhui Provincial Key Laboratory of Molecular Enzymology and Mechanism of Major Diseases, Key Laboratory of Biomedicine in Gene Diseases and Health of Anhui Higher Education Institutes, Anhui Normal University, Wuhu 241000, China
| | - Xuefei Chen
- Anhui Provincial Key Laboratory of Molecular Enzymology and Mechanism of Major Diseases, Key Laboratory of Biomedicine in Gene Diseases and Health of Anhui Higher Education Institutes, Anhui Normal University, Wuhu 241000, China
| | - Peng Wang
- Anhui Provincial Key Laboratory of Molecular Enzymology and Mechanism of Major Diseases, Key Laboratory of Biomedicine in Gene Diseases and Health of Anhui Higher Education Institutes, Anhui Normal University, Wuhu 241000, China
| | - Guoping Zhu
- Anhui Provincial Key Laboratory of Molecular Enzymology and Mechanism of Major Diseases, Key Laboratory of Biomedicine in Gene Diseases and Health of Anhui Higher Education Institutes, Anhui Normal University, Wuhu 241000, China
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Song P, Wang ML, Zheng QY, Wang P, Zhu GP. Isocitrate dehydrogenase 1 from Acinetobacter baummanii (AbIDH1) enzymatic characterization and its regulation by phosphorylation. Biochimie 2020; 181:77-85. [PMID: 33290880 DOI: 10.1016/j.biochi.2020.12.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 11/30/2020] [Accepted: 12/01/2020] [Indexed: 12/22/2022]
Abstract
Acinetobacter baumannii encodes all enzymes required in the tricarboxylic acid (TCA) cycle and glyoxylate bypass except for isocitrate dehydrogenase kinase/phosphatase (IDHKP), which can phosphorylate isocitrate dehydrogenase (IDH) at a substrate-binding Ser site and control the carbon flux in enterobacteria, such as Escherichia coli. The potential kinase was not successfully pulled down from A. baumannii cell lyase; therefore, whether the IDH 1 from A. baumannii (AbIDH1) can be phosphorylated to regulate intracellular carbon flux has not been clarified. Herein, the AbIDH1 gene was cloned, the encoded protein was expressed and purified to homogeneity, and phosphorylation and enzyme kinetics were evaluated in vitro. Gel filtration and SDS-PAGE analyses showed that AbIDH1 is an 83.5 kDa homodimer in solution. The kinetics showed that AbIDH1 is a fully active NADP-dependent enzyme. The Michaelis constant Km is 46.6 (Mn2+) and 18.1 μM (Mg2+) for NADP+ and 50.5 (Mn2+) and 65.4 μM (Mg2+) for the substrate isocitrate. Phosphorylation experiments in vitro indicated that AbIDH1 is a substrate for E. coli IDHKP. The activity of AbIDH1 treated with E. coli IDHKP immediately decreased by 80% within 9 min. Mass spectrometry indicated that the conserved Ser113 of AbIDH1 is phosphorylated. Continuous phosphorylation-mimicking mutants (Ser113Glu and Ser113Asp) lack almost all enzymatic activity. Side-chain mutations at Ser113 (Ser113Thr, Ser113Ala, Ser113Gly and Ser113Tyr) remarkably reduce the enzymatic activity. Understanding the potential of AbIDH1 phosphorylation enables further investigations of the AbIDH1 physiological functions in A. baumannii.
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Affiliation(s)
- Ping Song
- Anhui Provincial Key Laboratory of Molecular Enzymology and Mechanism of Major Diseases and Key Laboratory of Biomedicine in Gene Diseases and Health of Anhui Higher Education Institutes, Anhui Normal University, Wuhu, 241000, Anhui, China; College of Biological and Food Engineering, Anhui Polytechnic University, Wuhu, 241000, Anhui, China
| | - Meng-Li Wang
- Anhui Provincial Key Laboratory of Molecular Enzymology and Mechanism of Major Diseases and Key Laboratory of Biomedicine in Gene Diseases and Health of Anhui Higher Education Institutes, Anhui Normal University, Wuhu, 241000, Anhui, China
| | - Qing-Yang Zheng
- Anhui Provincial Key Laboratory of Molecular Enzymology and Mechanism of Major Diseases and Key Laboratory of Biomedicine in Gene Diseases and Health of Anhui Higher Education Institutes, Anhui Normal University, Wuhu, 241000, Anhui, China
| | - Peng Wang
- Anhui Provincial Key Laboratory of Molecular Enzymology and Mechanism of Major Diseases and Key Laboratory of Biomedicine in Gene Diseases and Health of Anhui Higher Education Institutes, Anhui Normal University, Wuhu, 241000, Anhui, China.
| | - Guo-Ping Zhu
- Anhui Provincial Key Laboratory of Molecular Enzymology and Mechanism of Major Diseases and Key Laboratory of Biomedicine in Gene Diseases and Health of Anhui Higher Education Institutes, Anhui Normal University, Wuhu, 241000, Anhui, China.
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Huang SP, Zhou LC, Wen B, Wang P, Zhu GP. Biochemical Characterization and Crystal Structure of a Novel NAD +-Dependent Isocitrate Dehydrogenase from Phaeodactylum tricornutum. Int J Mol Sci 2020; 21:ijms21165915. [PMID: 32824636 PMCID: PMC7460673 DOI: 10.3390/ijms21165915] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 08/11/2020] [Accepted: 08/13/2020] [Indexed: 12/12/2022] Open
Abstract
The marine diatom Phaeodactylum tricornutum originated from a series of secondary symbiotic events and has been used as a model organism for studying diatom biology. A novel type II homodimeric isocitrate dehydrogenase from P. tricornutum (PtIDH1) was expressed, purified, and identified in detail through enzymatic characterization. Kinetic analysis showed that PtIDH1 is NAD+-dependent and has no detectable activity with NADP+. The catalytic efficiency of PtIDH1 for NAD+ is 0.16 μM-1·s-1 and 0.09 μM-1·s-1 in the presence of Mn2+ and Mg2+, respectively. Unlike other bacterial homodimeric NAD-IDHs, PtIDH1 activity was allosterically regulated by the isocitrate. Furthermore, the dimeric structure of PtIDH1 was determined at 2.8 Å resolution, and each subunit was resolved into four domains, similar to the eukaryotic homodimeric NADP-IDH in the type II subfamily. Interestingly, a unique and novel C-terminal EF-hand domain was first defined in PtIDH1. Deletion of this domain disrupted the intact dimeric structure and activity. Mutation of the four Ca2+-binding sites in the EF-hand significantly reduced the calcium tolerance of PtIDH1. Thus, we suggest that the EF-hand domain could be involved in the dimerization and Ca2+-coordination of PtIDH1. The current report, on the first structure of type II eukaryotic NAD-IDH, provides new information for further investigation of the evolution of the IDH family.
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Wang P, Chen X, Yang J, Pei Y, Bian M, Zhu G. Characterization of the nicotinamide adenine dinucleotides (NAD + and NADP +) binding sites of the monomeric isocitrate dehydrogenases from Campylobacter species. Biochimie 2019; 160:148-155. [PMID: 30876971 DOI: 10.1016/j.biochi.2019.03.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Accepted: 03/10/2019] [Indexed: 12/15/2022]
Abstract
Monomeric isocitrate dehydrogenases (IDHs) have once been proposed to be exclusively NADP+-specific. Intriguingly, we recently have reported an NAD+-specific monomeric IDH from Campylobacter sp. FOBRC14 (CaIDH). Moreover, bioinformatic analysis revealed at least three different coenzyme-binding motifs among Campylobacter IDHs. Besides the NAD+-binding motif in CaIDH (Leu584/Asp595/Ser644), a typical NADP+-binding motif was also identified in Campylobacter corcagiensis IDH (CcoIDH, His582/Arg593/Arg638). Meanwhile, a third putative NAD+-binding motif was found in Campylobacter concisus IDH (CcIDH, Leu580/Leu591/Ala640). In this study, CcIDH was overexpressed in Escherichia coli and purified to homogeneity. Gel filtration chromatography demonstrated that the recombinant CcIDH exists as a monomer in solution. Kinetic analysis showed that the Km value of CcIDH for NADP+ was over 49-fold higher than that for NAD+ and the catalytic efficiency (kcat/Km) of CcIDH is 115-fold greater for NAD+ than NADP+. Thus, CcIDH is indeed an NAD+-specific enzyme. However, the catalytic efficiency (kcat/Km = 0.886 μM-1 s-1) of CcIDH for NAD+ is much lower (<5%) when compared to that of the typical monomeric NADP-IDHs for NADP+. Then, the three core NAD+-binding sites were evaluated by site-directed mutagenesis. The mutant CcIDH (H580R591R640) showed a 51-fold higher Km value for NAD+ and 21-fold lower Km value for NADP+ as compared to that of the wild type enzyme, respectively. The overall specificity of the mutant CcIDH was 12-fold greater for NADP+ than that for NAD+. Thus, the coenzyme specificity of CcIDH was converted from NAD+ to NADP+. Isocitrate dependence of enzyme kinetics showed that although the mutant H580R591R640 preferred NADP+ as its coenzyme, its catalytic efficiency for isocitrate reduced to half of that for the wild-type CcIDH as using NAD+. The finding of both NAD+ and NADP+-binding sites in monomeric IDHs from Campylobacter species will provide us a chance to explore the evolution of the coenzyme specificity in monomeric IDH subfamily.
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Affiliation(s)
- Peng Wang
- Institute of Molecular Biology and Biotechnology and the Research Center of Life Omics and Health, College of Life Sciences, Anhui Normal University, Wuhu, 241000, Anhui, China
| | - Xuefei Chen
- Institute of Molecular Biology and Biotechnology and the Research Center of Life Omics and Health, College of Life Sciences, Anhui Normal University, Wuhu, 241000, Anhui, China
| | - Jing Yang
- Institute of Molecular Biology and Biotechnology and the Research Center of Life Omics and Health, College of Life Sciences, Anhui Normal University, Wuhu, 241000, Anhui, China
| | - Yunyun Pei
- Institute of Molecular Biology and Biotechnology and the Research Center of Life Omics and Health, College of Life Sciences, Anhui Normal University, Wuhu, 241000, Anhui, China
| | - Mingjie Bian
- Institute of Molecular Biology and Biotechnology and the Research Center of Life Omics and Health, College of Life Sciences, Anhui Normal University, Wuhu, 241000, Anhui, China
| | - Guoping Zhu
- Institute of Molecular Biology and Biotechnology and the Research Center of Life Omics and Health, College of Life Sciences, Anhui Normal University, Wuhu, 241000, Anhui, China.
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Bian M, Li S, Wei H, Huang S, Zhou F, Zhu Y, Zhu G. Heteroexpression and biochemical characterization of a glucose-6-phosphate dehydrogenase from oleaginous yeast Yarrowia lipolytica. Protein Expr Purif 2018; 148:1-8. [PMID: 29580928 DOI: 10.1016/j.pep.2018.03.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2017] [Revised: 02/07/2018] [Accepted: 03/21/2018] [Indexed: 01/08/2023]
Abstract
Yarrowia lipolytica, a nonpathogenic, nonconventional, aerobic and dimorphic yeast, is considered an oleaginous microorganism due to its excellent ability to accumulate large amounts of lipids. Glucose-6-phosphate dehydrogenase (G6PD) is one of two key enzymes involved in the lipid accumulation in this fungi, which catalyzes the oxidative dehydrogenation of glucose-6-phosphate to 6-phosphoglucono-δ-lactone with the reduction of NADP+ to NADPH. In this study, the full-length gene of G6PD from Y. lipolytica (YlG6PD) was cloned without intron and heterogeneously expressed in E. coli. Then, YlG6PD was purified and biochemically characterized in details. Kinetic analysis showed that YlG6PD was completely dependent on NADP+ and its apparent Km for NADP+ was 33.3 μM. The optimal pH was 8.5 and the maximum activity was around 47.5 °C. Heat-inactivation profiles revealed that it remained 50% of maximal activity after incubation at 48 °C for 20 min YlG6PD activity was competitively inhibited by NADPH with a Ki value of 56.04 μM. Most of the metal ions have no effect on activity, but Zn2+ was a strong inhibitor. Furthermore, the determinants in the coenzyme specificity of YlG6PD were investigated. Kinetic analysis showed that the single mutant R52D completely lost the ability to utilize NADP+ as its coenzyme, suggesting that Arg-52 plays a decisive role in NADP+ binding in YlG6PD. The identification of Y. lipolytica G6PD may provide useful scientific information for metabolic engineering of this yeast as a model for bio-oil production.
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Affiliation(s)
- Mingjie Bian
- Institute of Molecular Biology and Biotechnology and the Research Center of Life Omics and Health, Anhui Normal University, No.1 Beijing East Road, Wuhu 241000, Anhui, China
| | - Shan Li
- Institute of Molecular Biology and Biotechnology and the Research Center of Life Omics and Health, Anhui Normal University, No.1 Beijing East Road, Wuhu 241000, Anhui, China
| | - Huanhuan Wei
- Institute of Molecular Biology and Biotechnology and the Research Center of Life Omics and Health, Anhui Normal University, No.1 Beijing East Road, Wuhu 241000, Anhui, China
| | - Shiping Huang
- Institute of Molecular Biology and Biotechnology and the Research Center of Life Omics and Health, Anhui Normal University, No.1 Beijing East Road, Wuhu 241000, Anhui, China
| | - Feng Zhou
- Institute of Molecular Biology and Biotechnology and the Research Center of Life Omics and Health, Anhui Normal University, No.1 Beijing East Road, Wuhu 241000, Anhui, China
| | - Youming Zhu
- Department of Oral and Maxillofacial Surgery, School of Stomatology, Stomatological Hospital, Anhui Medical University, No.81 Mei Shan Road, Hefei 230032, Anhui, China.
| | - Guoping Zhu
- Institute of Molecular Biology and Biotechnology and the Research Center of Life Omics and Health, Anhui Normal University, No.1 Beijing East Road, Wuhu 241000, Anhui, China.
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Romkina AY, Kiriukhin MY. Biochemical and molecular characterization of the isocitrate dehydrogenase with dual coenzyme specificity from the obligate methylotroph Methylobacillus Flagellatus. PLoS One 2017; 12:e0176056. [PMID: 28423051 PMCID: PMC5397045 DOI: 10.1371/journal.pone.0176056] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Accepted: 04/04/2017] [Indexed: 12/16/2022] Open
Abstract
The isocitrate dehydrogenase (MfIDH) with unique double coenzyme specificity from Methylobacillus flagellatus was purified and characterized, and its gene was cloned and overexpressed in E. coli as a fused protein. This enzyme is homodimeric,—with a subunit molecular mass of 45 kDa and a specific activity of 182 U mg -1 with NAD+ and 63 U mg -1 with NADP+. The MfIDH activity was dependent on divalent cations and Mn2+ enhanced the activity the most effectively. MfIDH exhibited a cofactor-dependent pH-activity profile. The optimum pH values were 8.5 (NAD+) and 6.0 (NADP+).The Km values for NAD+ and NADP+ were 113 μM and 184 μM respectively, while the Km values for DL-isocitrate were 9.0 μM (NAD+), 8.0 μM (NADP+). The MfIDH specificity (kcat/Km) was only 5-times higher for NAD+ than for NADP+. The purified MfIDH displayed maximal activity at 60°C. Heat-inactivation studies showed that the MfIDH was remarkably thermostable, retaining full activity at 50°C and losting ca. 50% of its activity after one hour of incubation at 75°C. The enzyme was insensitive to the presence of intermediate metabolites, with the exception of 2 mM ATP, which caused 50% inhibition of NADP+-linked activity. The indispensability of the N6 amino group of NAD(P)+ in its binding to MfIDH was demonstrated. MfIDH showed high sequence similarity with bacterial NAD(P)+-dependent type I isocitrate dehydrogenases (IDHs) rather than with eukaryotic NAD+-dependent IDHs. The unique double coenzyme specificity of MfIDH potentially resulted from the Lys340, Ile341 and Ala347 residues in the coenzyme-binding site of the enzyme. The discovery of a type I IDH with double coenzyme specificity elucidates the evolution of this subfamily IDHs and may provide fundamental information for engineering enzymes with desired properties.
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Willenborg J, Goethe R. Metabolic traits of pathogenic streptococci. FEBS Lett 2016; 590:3905-3919. [PMID: 27442496 DOI: 10.1002/1873-3468.12317] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Revised: 07/12/2016] [Accepted: 07/18/2016] [Indexed: 12/13/2022]
Abstract
Invasive and noninvasive diseases caused by facultative pathogenic streptococci depend on their equipment with virulence factors and on their ability to sense and adapt to changing nutrients in different host environments. The knowledge of the principal metabolic mechanisms which allow these bacteria to recognize and utilize nutrients in host habitats is a prerequisite for our understanding of streptococcal pathogenicity and the development of novel control strategies. This review aims to summarize and compare the central carbohydrate metabolic and amino acid biosynthetic pathways of a selected group of streptococcal species, all belonging to the naso-oropharyngeal microbiome in humans and/or animals. We also discuss the urgent need of comprehensive metabolomics approaches for a better understanding of the streptococcal metabolism during host-pathogen interaction.
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Affiliation(s)
- Jörg Willenborg
- Institute for Microbiology, University of Veterinary Medicine Hannover, Germany
| | - Ralph Goethe
- Institute for Microbiology, University of Veterinary Medicine Hannover, Germany
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Lv C, Wang P, Wang W, Su R, Ge Y, Zhu Y, Zhu G. Two isocitrate dehydrogenases from a plant pathogen Xanthomonas campestris pv. campestris 8004. Bioinformatic analysis, enzymatic characterization, and implication in virulence. J Basic Microbiol 2016; 56:975-85. [PMID: 27282849 DOI: 10.1002/jobm.201500648] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Accepted: 03/28/2016] [Indexed: 12/16/2022]
Abstract
Isocitrate dehydrogenase (IDH) is a key enzyme in the tricarboxylate (TCA) cycle, which may play an important role in the virulence of pathogenic bacteria. Here, two structurally different IDHs from a plant pathogen Xanthomonas campestris pv. campestris 8004 (XccIDH1 and XccIDH2) were characterized in detail. The recombinant XccIDH1 forms homodimer in solution, while the recombinant XccIDH2 is a typical monomer. Phylogenetic analysis showed that XccIDH1 belongs to the type I IDH subfamily and XccIDH2 groups into the monomeric IDH clade. Kinetic characterization demonstrated that XccIDH1's specificity towards NAD(+) was 110-fold greater than NADP(+) , while XccIDH2's specificity towards NADP(+) was 353-fold greater than NAD(+) . The putative coenzyme discriminating amino acids (Asp268, Ile269 and Ala275 for XccIDH1, and Lys589, His590 and Arg601 for XccIDH2) were studied by site-directed mutagenesis. The coenzyme specificities of the two mutants, mXccIDH1 and mXccIDH2, were completely reversed from NAD(+) to NADP(+) , and NADP(+) to NAD(+) , respectively. Furthermore, Ser80 of XccIDH1, and Lys256 and Tyr421 of XccIDH2, were the determinants for the substrate binding. The detailed biochemical properties, such as optimal pH and temperature, thermostability, and metal ion effects, of XccIDH1 and XccIDH2 were further investigated. The possibility of taking the two IDHs into consideration as the targets for drug development to control the plant diseases caused by Xcc 8004 were described and discussed thoroughly.
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Affiliation(s)
- Changqi Lv
- Institute of Molecular Biology and Biotechnology, College of Life Sciences, Anhui Normal University, China
| | - Peng Wang
- Institute of Molecular Biology and Biotechnology, College of Life Sciences, Anhui Normal University, China
| | - Wencai Wang
- Institute of Molecular Biology and Biotechnology, College of Life Sciences, Anhui Normal University, China
| | - Ruirui Su
- Institute of Molecular Biology and Biotechnology, College of Life Sciences, Anhui Normal University, China
| | - Yadong Ge
- Institute of Molecular Biology and Biotechnology, College of Life Sciences, Anhui Normal University, China
| | - Youming Zhu
- Department of Oral and Maxillofacial Surgery, School of Stomatology, Stomatological Hospital, Anhui Medical University, China.
| | - Guoping Zhu
- Institute of Molecular Biology and Biotechnology, College of Life Sciences, Anhui Normal University, China.
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Biochemical Characterization and Complete Conversion of Coenzyme Specificity of Isocitrate Dehydrogenase from Bifidobacterium longum. Int J Mol Sci 2016; 17:296. [PMID: 26927087 PMCID: PMC4813160 DOI: 10.3390/ijms17030296] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2016] [Revised: 02/09/2016] [Accepted: 02/19/2016] [Indexed: 12/15/2022] Open
Abstract
Bifidobacterium longum is a very important gram-positive non-pathogenic bacterium in the human gastrointestinal tract for keeping the digestive and immune system healthy. Isocitrate dehydrogenase (IDH) from B. longum (BlIDH), a novel member in Type II subfamily, was overexpressed, purified and biochemically characterized in detail. The active form of BlIDH was an 83-kDa homodimer. Kinetic analysis showed BlIDH was a NADP⁺-dependent IDH (NADP-IDH), with a 567- and 193-fold preference for NADP⁺ over NAD⁺ in the presence of Mg(2+) and Mn(2+), respectively. The maximal activity for BlIDH occurred at 60 °C (with Mn(2+)) and 65 °C (with Mg(2+)), and pH 7.5 (with Mn(2+)) and pH 8.0 (with Mg(2+)). Heat-inactivation profiles revealed that BlIDH retained 50% of maximal activity after incubation at 45 °C for 20 min with either Mn(2+) or Mg(2+). Furthermore, the coenzyme specificity of BlIDH can be completely reversed from NADP⁺ to NAD⁺ by a factor of 2387 by replacing six residues. This current work, the first report on the coenzyme specificity conversion of Type II NADP-IDHs, would provide better insight into the evolution of NADP⁺ use by the IDH family.
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Spaans SK, Weusthuis RA, van der Oost J, Kengen SWM. NADPH-generating systems in bacteria and archaea. Front Microbiol 2015; 6:742. [PMID: 26284036 PMCID: PMC4518329 DOI: 10.3389/fmicb.2015.00742] [Citation(s) in RCA: 197] [Impact Index Per Article: 21.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Accepted: 07/06/2015] [Indexed: 12/22/2022] Open
Abstract
Reduced nicotinamide adenine dinucleotide phosphate (NADPH) is an essential electron donor in all organisms. It provides the reducing power that drives numerous anabolic reactions, including those responsible for the biosynthesis of all major cell components and many products in biotechnology. The efficient synthesis of many of these products, however, is limited by the rate of NADPH regeneration. Hence, a thorough understanding of the reactions involved in the generation of NADPH is required to increase its turnover through rational strain improvement. Traditionally, the main engineering targets for increasing NADPH availability have included the dehydrogenase reactions of the oxidative pentose phosphate pathway and the isocitrate dehydrogenase step of the tricarboxylic acid (TCA) cycle. However, the importance of alternative NADPH-generating reactions has recently become evident. In the current review, the major canonical and non-canonical reactions involved in the production and regeneration of NADPH in prokaryotes are described, and their key enzymes are discussed. In addition, an overview of how different enzymes have been applied to increase NADPH availability and thereby enhance productivity is provided.
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Affiliation(s)
| | - Ruud A. Weusthuis
- Bioprocess Engineering, Wageningen UniversityWageningen, Netherlands
| | - John van der Oost
- Laboratory of Microbiology, Wageningen UniversityWageningen, Netherlands
| | - Servé W. M. Kengen
- Laboratory of Microbiology, Wageningen UniversityWageningen, Netherlands
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Wu MC, Tian CQ, Cheng HM, Xu L, Wang P, Zhu GP. A Novel Type II NAD+-Specific Isocitrate Dehydrogenase from the Marine Bacterium Congregibacter litoralis KT71. PLoS One 2015; 10:e0125229. [PMID: 25942017 PMCID: PMC4420465 DOI: 10.1371/journal.pone.0125229] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2014] [Accepted: 03/22/2015] [Indexed: 11/29/2022] Open
Abstract
In most living organisms, isocitrate dehydrogenases (IDHs) convert isocitrate into ɑ-ketoglutarate (ɑ-KG). Phylogenetic analyses divide the IDH protein family into two subgroups: types I and II. Based on cofactor usage, IDHs are either NAD+-specific (NAD-IDH) or NADP+-specific (NADP-IDH); NADP-IDH evolved from NAD-IDH. Type I IDHs include NAD-IDHs and NADP-IDHs; however, no type II NAD-IDHs have been reported to date. This study reports a novel type II NAD-IDH from the marine bacterium Congregibacter litoralis KT71 (ClIDH, GenBank accession no. EAQ96042). His-tagged recombinant ClIDH was produced in Escherichia coli and purified; the recombinant enzyme was NAD+-specific and showed no detectable activity with NADP+. The Km values of the enzyme for NAD+ were 262.6±7.4 μM or 309.1±11.2 μM with Mg2+ or Mn2+ as the divalent cation, respectively. The coenzyme specificity of a ClIDH Asp487Arg/Leu488His mutant was altered, and the preference of the mutant for NADP+ was approximately 24-fold higher than that for NAD+, suggesting that ClIDH is an NAD+-specific ancestral enzyme in the type II IDH subgroup. Gel filtration and analytical ultracentrifugation analyses revealed the homohexameric structure of ClIDH, which is the first IDH hexamer discovered thus far. A 163-amino acid segment of CIIDH is essential to maintain its polymerization structure and activity, as a truncated version lacking this region forms a non-functional monomer. ClIDH was dependent on divalent cations, the most effective being Mn2+. The maximal activity of purified recombinant ClIDH was achieved at 35°C and pH 7.5, and a heat inactivation experiment showed that a 20-min incubation at 33°C caused a 50% loss of ClIDH activity. The discovery of a NAD+-specific, type II IDH fills a gap in the current classification of IDHs, and sheds light on the evolution of type II IDHs.
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Affiliation(s)
- Ming-Cai Wu
- Institute of Molecular Biology and Biotechnology, Anhui Normal University, No. 1 Beijing East Road, Wuhu, 241000, Anhui, China
- Anhui Province Key Laboratory of Active Biological Macro-molecules, Wannan Medical College, No. 22 Wenchang West Road, Wuhu, 241002, Anhui, China
| | - Chang-Qing Tian
- Institute of Molecular Biology and Biotechnology, Anhui Normal University, No. 1 Beijing East Road, Wuhu, 241000, Anhui, China
| | - Hong-Mei Cheng
- Institute of Molecular Biology and Biotechnology, Anhui Normal University, No. 1 Beijing East Road, Wuhu, 241000, Anhui, China
| | - Lei Xu
- Institute of Molecular Biology and Biotechnology, Anhui Normal University, No. 1 Beijing East Road, Wuhu, 241000, Anhui, China
- Anhui Province Key Laboratory of Active Biological Macro-molecules, Wannan Medical College, No. 22 Wenchang West Road, Wuhu, 241002, Anhui, China
| | - Peng Wang
- Institute of Molecular Biology and Biotechnology, Anhui Normal University, No. 1 Beijing East Road, Wuhu, 241000, Anhui, China
- * E-mail: (PW); (G-PZ)
| | - Guo-Ping Zhu
- Institute of Molecular Biology and Biotechnology, Anhui Normal University, No. 1 Beijing East Road, Wuhu, 241000, Anhui, China
- * E-mail: (PW); (G-PZ)
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Wang P, Lv C, Zhu G. Novel type II and monomeric NAD+ specific isocitrate dehydrogenases: phylogenetic affinity, enzymatic characterization, and evolutionary implication. Sci Rep 2015; 5:9150. [PMID: 25775177 PMCID: PMC4360740 DOI: 10.1038/srep09150] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Accepted: 02/23/2015] [Indexed: 11/09/2022] Open
Abstract
NAD(+) use is an ancestral trait of isocitrate dehydrogenase (IDH), and the NADP(+) phenotype arose through evolution as an ancient adaptation event. However, no NAD(+)-specific IDHs have been found among type II IDHs and monomeric IDHs. In this study, novel type II homodimeric NAD-IDHs from Ostreococcus lucimarinus CCE9901 IDH (OlIDH) and Micromonas sp. RCC299 (MiIDH), and novel monomeric NAD-IDHs from Campylobacter sp. FOBRC14 IDH (CaIDH) and Campylobacter curvus (CcIDH) were reported for the first time. The homodimeric OlIDH and monomeric CaIDH were determined by size exclusion chromatography and MALDI-TOF/TOF mass spectrometry. All the four IDHs were demonstrated to be NAD(+)-specific, since OlIDH, MiIDH, CaIDH and CcIDH displayed 99-fold, 224-fold, 61-fold and 37-fold preferences for NAD(+) over NADP(+), respectively. The putative coenzyme discriminating amino acids (Asp326/Met327 in OlIDH, Leu584/Asp595 in CaIDH) were evaluated, and the coenzyme specificities of the two mutants, OlIDH R(326)H(327) and CaIDH H(584)R(595), were completely reversed from NAD(+) to NADP(+). The detailed biochemical properties, including optimal reaction pH and temperature, thermostability, and metal ion effects, of OlIDH and CaIDH were further investigated. The evolutionary connections among OlIDH, CaIDH, and all the other forms of IDHs were described and discussed thoroughly.
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Affiliation(s)
- Peng Wang
- Institute of Molecular Biology and Biotechnology, College of Life Sciences, Anhui Normal University, No.1 Beijing East Road, Wuhu 241000, Anhui, China
| | - Changqi Lv
- Institute of Molecular Biology and Biotechnology, College of Life Sciences, Anhui Normal University, No.1 Beijing East Road, Wuhu 241000, Anhui, China
| | - Guoping Zhu
- Institute of Molecular Biology and Biotechnology, College of Life Sciences, Anhui Normal University, No.1 Beijing East Road, Wuhu 241000, Anhui, China
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Isocitrate dehydrogenase from Streptococcus mutans: biochemical properties and evaluation of a putative phosphorylation site at Ser102. PLoS One 2013; 8:e58918. [PMID: 23484056 PMCID: PMC3590139 DOI: 10.1371/journal.pone.0058918] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2012] [Accepted: 02/08/2013] [Indexed: 11/30/2022] Open
Abstract
Isocitrate deyhdrogenase (IDH) is a reversible enzyme in the tricarboxylic acid cycle that catalyzes the NAD(P)+-dependent oxidative decarboxylation of isocitrate to α-ketoglutarate (αKG) and the NAD(P)H/CO2-dependent reductive carboxylation of αKG to isocitrate. The IDH gene from Streptococcus mutans was fused with the icd gene promoter from Escherichia coli to initiate its expression in the glutamate auxotrophic strain E. coli Δicd::kanr of which the icd gene has been replaced by kanamycin resistance gene. The expression of S. mutans IDH (SmIDH) may restore the wild-type phenotype of the icd-defective strain on minimal medium without glutamate. The molecular weight of SmIDH was estimated to be 70 kDa by gel filtration chromatography, suggesting a homodimeric structure. SmIDH was divalent cation-dependent and Mn2+ was found to be the most effective cation. The optimal pH of SmIDH was 7.8 and the maximum activity was around 45°C. SmIDH was completely NAD+ dependent and its apparent Km for NAD+ was 137 μM. In order to evaluate the role of the putative phosphorylation site at Ser102 in catalysis, two “stably phosphorylated” mutants were constructed by converting Ser102 into Glu102 or Asp102 in SmIDH to mimick a constitutively phosphorylated state. Meanwhile, the functional roles of another four amino acids (threonine, glycine, alanine and tyrosine) containing variant size of side chains were investigated. The replacement of Asp102 or Glu102 totally inactivated the enzyme, while the S102T, S102G, S102A and S102Y mutants decreased the affinity to isocitrate and only retained 16.0%, 2.8%, 3.3% and 1.1% of the original activity, respectively. These results reveal that Ser102 plays important role in substrate binding and is required for the enzyme function. Also, Ser102 in SmIDH is a potential phosphorylation site, indicating that the ancient NAD-dependent IDHs might be the underlying origin of “phosphorylation mechanism” used by their bacterial NADP-dependent homologs.
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