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Hübner I, Shapiro JA, Hoßmann J, Drechsel J, Hacker SM, Rather PN, Pieper DH, Wuest WM, Sieber SA. Broad Spectrum Antibiotic Xanthocillin X Effectively Kills Acinetobacter baumannii via Dysregulation of Heme Biosynthesis. ACS CENTRAL SCIENCE 2021; 7:488-498. [PMID: 33791430 PMCID: PMC8006170 DOI: 10.1021/acscentsci.0c01621] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Indexed: 05/19/2023]
Abstract
Isonitrile natural products exhibit promising antibacterial activities. However, their mechanism of action (MoA) remains largely unknown. Based on the nanomolar potency of xanthocillin X (Xan) against diverse difficult-to-treat Gram-negative bacteria, including the critical priority pathogen Acinetobacter baumannii, we performed in-depth studies to decipher its MoA. While neither metal binding nor cellular protein targets were detected as relevant for Xan's antibiotic effects, sequencing of resistant strains revealed a conserved mutation in the heme biosynthesis enzyme porphobilinogen synthase (PbgS). This mutation caused impaired enzymatic efficiency indicative of reduced heme production. This discovery led to the validation of an untapped mechanism, by which direct heme sequestration of Xan prevents its binding into cognate enzyme pockets resulting in uncontrolled cofactor biosynthesis, accumulation of porphyrins, and corresponding stress with deleterious effects for bacterial viability. Thus, Xan represents a promising antibiotic displaying activity even against multidrug resistant strains, while exhibiting low toxicity to human cells.
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Affiliation(s)
- Ines Hübner
- Center
for Functional Protein Assemblies at the Department of Chemistry and
Chair of Organic Chemistry II, Technische
Universität München, Garching D-85748, Germany
| | - Justin A. Shapiro
- Department
of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| | - Jörn Hoßmann
- Microbial
Interactions and Processes Research Group, Helmholtz Centre for Infection Research, Braunschweig 38124, Germany
| | - Jonas Drechsel
- Center
for Functional Protein Assemblies at the Department of Chemistry and
Chair of Organic Chemistry II, Technische
Universität München, Garching D-85748, Germany
| | - Stephan M. Hacker
- Department
of Chemistry, Technische Universität
München, Garching D-85748, Germany
| | - Philip N. Rather
- Emory Antibiotic Resistance Center and Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia 30322, United States
- Research
Service, Atlanta VA Medical Center, Decatur, Georgia 30033, United States
| | - Dietmar H. Pieper
- Microbial
Interactions and Processes Research Group, Helmholtz Centre for Infection Research, Braunschweig 38124, Germany
| | - William M. Wuest
- Department
of Chemistry, Emory University, Atlanta, Georgia 30322, United States
- Emory Antibiotic Resistance Center and Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia 30322, United States
| | - Stephan A. Sieber
- Center
for Functional Protein Assemblies at the Department of Chemistry and
Chair of Organic Chemistry II, Technische
Universität München, Garching D-85748, Germany
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Transcription in the acetoin catabolic pathway is regulated by AcoR and CcpA in Bacillus thuringiensis. Microbiol Res 2020; 235:126438. [PMID: 32088504 DOI: 10.1016/j.micres.2020.126438] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2019] [Revised: 02/11/2020] [Accepted: 02/11/2020] [Indexed: 01/04/2023]
Abstract
Acetoin (3-hydroxy-2-butanone) is an important physiological metabolic product in many microorganisms. Acetoin breakdown is catalyzed by the acetoin dehydrogenase enzyme system (AoDH ES), which is encoded by acoABCL operon. In this study, we analyzed transcription and regulation of the aco operon in Bacillus thuringiensis (Bt). RT-PCR analysis revealed that acoABCL forms one transcriptional unit. The Sigma 54 controlled consensus sequence was located 12 bp from the acoA transcriptional start site (TSS). β-galactosidase assay revealed that aco operon transcription is induced by acetoin, controlled by sigma 54, and positively regulated by AcoR. The HTH domain of AcoR recognized and specifically bound to a 13-bp inverted repeat region that participates in 30-bp fragment mapping 81 bp upstream of the acoA TSS. The GAF domain in AcoR represses enhancer transcriptional activity at the acoA promoter. Transcriptions of the aco operon and acoR were repressed by glucose via CcpA, and CcpA specifically bound to sequences within the acoR promoter fragment. In the acoABCL and acoR mutants, acetoin use was abolished, suggesting that the aco operon is essential for utilization of acetoin. The data presented here improve our understanding of the regulation of the aco gene cluster in bacteria.
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2,3-Butanediol fermentation promotes growth of Serratia plymuthica at low pH but not survival of extreme acid challenge. Int J Food Microbiol 2014; 175:36-44. [DOI: 10.1016/j.ijfoodmicro.2014.01.017] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2013] [Revised: 01/23/2014] [Accepted: 01/26/2014] [Indexed: 01/10/2023]
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Ramos PIP, Picão RC, Almeida LGPD, Lima NCB, Girardello R, Vivan ACP, Xavier DE, Barcellos FG, Pelisson M, Vespero EC, Médigue C, Vasconcelos ATRD, Gales AC, Nicolás MF. Comparative analysis of the complete genome of KPC-2-producing Klebsiella pneumoniae Kp13 reveals remarkable genome plasticity and a wide repertoire of virulence and resistance mechanisms. BMC Genomics 2014; 15:54. [PMID: 24450656 PMCID: PMC3904158 DOI: 10.1186/1471-2164-15-54] [Citation(s) in RCA: 84] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2013] [Accepted: 12/26/2013] [Indexed: 11/24/2022] Open
Abstract
Background Klebsiella pneumoniae is an important opportunistic pathogen associated with nosocomial and community-acquired infections. A wide repertoire of virulence and antimicrobial resistance genes is present in K. pneumoniae genomes, which can constitute extra challenges in the treatment of infections caused by some strains. K. pneumoniae Kp13 is a multidrug-resistant strain responsible for causing a large nosocomial outbreak in a teaching hospital located in Southern Brazil. Kp13 produces K. pneumoniae carbapenemase (KPC-2) but is unrelated to isolates belonging to ST 258 and ST 11, the main clusters associated with the worldwide dissemination of KPC-producing K. pneumoniae. In this report, we perform a genomic comparison between Kp13 and each of the following three K. pneumoniae genomes: MGH 78578, NTUH-K2044 and 342. Results We have completely determined the genome of K. pneumoniae Kp13, which comprises one chromosome (5.3 Mbp) and six plasmids (0.43 Mbp). Several virulence and resistance determinants were identified in strain Kp13. Specifically, we detected genes coding for six beta-lactamases (SHV-12, OXA-9, TEM-1, CTX-M-2, SHV-110 and KPC-2), eight adhesin-related gene clusters, including regions coding for types 1 (fim) and 3 (mrk) fimbrial adhesins. The rmtG plasmidial 16S rRNA methyltransferase gene was also detected, as well as efflux pumps belonging to five different families. Mutations upstream the OmpK35 porin-encoding gene were evidenced, possibly affecting its expression. SNPs analysis relative to the compared strains revealed 141 mutations falling within CDSs related to drug resistance which could also influence the Kp13 lifestyle. Finally, the genetic apparatus for synthesis of the yersiniabactin siderophore was identified within a plasticity region. Chromosomal architectural analysis allowed for the detection of 13 regions of difference in Kp13 relative to the compared strains. Conclusions Our results indicate that the plasticity occurring at many hierarchical levels (from whole genomic segments to individual nucleotide bases) may play a role on the lifestyle of K. pneumoniae Kp13 and underlie the importance of whole-genome sequencing to study bacterial pathogens. The general chromosomal structure was somewhat conserved among the compared bacteria, and recombination events with consequent gain/loss of genomic segments appears to be driving the evolution of these strains.
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Identification of acetoin reductases involved in 2,3-butanediol pathway in Klebsiella oxytoca. J Biotechnol 2013; 172:59-66. [PMID: 24389066 DOI: 10.1016/j.jbiotec.2013.12.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2013] [Revised: 12/05/2013] [Accepted: 12/10/2013] [Indexed: 11/22/2022]
Abstract
The acetoin reductase (AR) of Klebsiella oxytoca is responsible for converting acetoin into 2,3-butanediol (2,3-BDO) during sugar fermentation. Deleting the AR encoding gene (budC) in the 2,3-BDO operon does not block production of 2,3-BDO, as another similar gene exists in addition to budC called diacetyl/acetoin reductase (dar) which shares 53% identity with budC. In the present study, both budC and dar of K. oxytoca were independently cloned and expressed in Escherichia coli along with budA (acetolactate decarboxylase) and budB (acetolactate synthase), which are responsible for converting pyruvate into acetoin. The recombinant E. coli expressing budABC and budAB-dar produced 2,3-BDO from glucose but E. coli expressing only budAB did not and produced acetoin alone. This demonstrates that Dar functions similar to BudC. Mutants of budC, dar, and both genes together were developed in K. oxytoca ΔldhA (lactate dehydrogenase). K. oxytoca ΔldhA ΔbudC Δdar, deficient in both AR genes, showed reduced 2,3-BDO concentration when compared to K. oxytoca ΔldhA and K. oxytoca ΔldhA ΔbudC by 84% and 69%, respectively. Interestingly, K. oxytoca ΔldhA Δdar resulted in a significant reduction in the reversible conversion of 2,3-BDO into acetoin than that of K. oxytoca ΔldhA, which was observed in a glucose depleted fermentation culture. In addition, we observed that Dar played a key role in dissimilation of 2,3-BDO in media containing 2,3-BDO alone.
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Abstract
Lipoic acid [(R)-5-(1,2-dithiolan-3-yl)pentanoic acid] is an enzyme cofactor required for intermediate metabolism in free-living cells. Lipoic acid was discovered nearly 60 years ago and was shown to be covalently attached to proteins in several multicomponent dehydrogenases. Cells can acquire lipoate (the deprotonated charge form of lipoic acid that dominates at physiological pH) through either scavenging or de novo synthesis. Microbial pathogens implement these basic lipoylation strategies with a surprising variety of adaptations which can affect pathogenesis and virulence. Similarly, lipoylated proteins are responsible for effects beyond their classical roles in catalysis. These include roles in oxidative defense, bacterial sporulation, and gene expression. This review surveys the role of lipoate metabolism in bacterial, fungal, and protozoan pathogens and how these organisms have employed this metabolism to adapt to niche environments.
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Hsu JL, Peng HL, Chang HY. The ATP-binding motif in AcoK is required for regulation of acetoin catabolism in Klebsiella pneumoniae CG43. Biochem Biophys Res Commun 2008; 376:121-7. [PMID: 18765233 DOI: 10.1016/j.bbrc.2008.08.103] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2008] [Accepted: 08/22/2008] [Indexed: 11/26/2022]
Abstract
Many bacterial species utilize acetoin as a carbon source. In Klebsiella pneumoniae, the utilization of acetoin is catalyzed by an acetoin dehydrogenase complex encoded by the acoABCD operon, which is positively regulated in the presence of acetoin by the transcriptional factor AcoK. AcoK contains a LuxR type DNA-binding domain at the C-terminal region and putative Walker A and B nucleotide-binding motifs in the N-terminal region. The comprehensive deletion and mutation study performed here shows that mutations in the putative Walker A motif result in a significant reduction of ATP hydrolysis and trans-activation by AcoK of acoABCD expression, presumably due to a loss of ATP-binding ability. AcoK was shown to bind specifically to nucleotides -66 to -36 of the acoABCD promoter, though the DNA-binding ability was not affected by the Walker A motif mutation. Thus, this study provides an additional example of how a member of the signal transduction ATPases with numerous domains family activates its target gene expression.
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Affiliation(s)
- Jye-Lin Hsu
- Institute of Molecular Medicine, National Tsing Hua University, 101 Kuang Fu Road 2nd Section, Hsin Chu 300, Taiwan, ROC
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8
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Abstract
Acetoin is an important physiological metabolite excreted by many microorganisms. The excretion of acetoin, which can be diagnosed by the Voges Proskauer test and serves as a microbial classification marker, has its vital physiological meanings to these microbes mainly including avoiding acification, participating in the regulation of NAD/NADH ratio, and storaging carbon. The well-known anabolism of acetoin involves alpha-acetolactat synthase and alpha-acetolactate decarboxylase; yet its catabolism still contains some differing views, although much attention has been focused on it and great advances have been achieved. Current findings in catabolite control protein A (CcpA) mediated carbon catabolite repression may provide a fuller understanding of the control mechanism in bacteria. In this review, we first examine the acetoin synthesis pathways and its physiological meanings and relevancies; then we discuss the relationship between the two conflicting acetoin cleavage pathways, the enzymes of the acetoin dehydrogenase enzyme system, major genes involved in acetoin degradation, and the CcpA mediated acetoin catabolite repression pathway; in the end we discuss the genetic engineering progresses concerning applications. To date, this is the first integrated review on acetoin metabolism in bacteria, especially with regard to catabolic aspects. The apperception of the generation and dissimilation of acetoin in bacteria will help provide a better understanding of microbial strategies in the struggle for resources, which will consequently better serve the utilization of these microbes.
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Affiliation(s)
- Zijun Xiao
- State Key Laboratory of Microbial Technology, Shandong University, People's Republic of China
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Pedroni P, Friedrich T, Breuer M, McBeth D, Hauer B. Novel esterase activity of dihydrolipoamide acetyltransferase AcoC of Pseudomonas putida identified by mutation of the acoR regulator. CAN J CHEM 2002. [DOI: 10.1139/v02-080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A mutant strain of Pseudomonas putida (LU2201) expressing a novel ethylphenylacetate (EPA) esterase was isolated after mutagenesis of P. putida LU6456. The DNA fragment conferring the EPA+ phenotype was cloned and characterized. It included the structural genes of the 2,3-butanediol catabolic pathway, including acoC, which catalyzes the acetyl transfer step (i.e., dihydrolipoamide acetyltransferase). The acoC gene product from LU2201 was expressed in E. coli and shown to be responsible for the novel EPA-esterase activity. Biochemical characterization revealed that the enzyme still retained the natural dihydrolipoamide acetyltransferase activity. Sequence comparison with the corresponding wild-type gene indicated a single-base pair change leading to a I238V replacement in the respective protein. Biochemical characterization of wild-type AcoC enzyme showed that it too was able to catalyze EPA hydrolysis despite the apparent absence of this activity in cells grown in the presence of EPA. Unlike the wild type, EPA serves as an inducer in the mutant strain. Inverse PCR was used to clone the putative regulator acoR from the aco operon in both wild type and mutant strains. Sequence analyses indicated an S14R exchange in the AcoR from the P. putida mutant. This mutation was located in the N-terminal region responsible for regulatory functions, presumably by interaction with signal molecules. This may account for the ability of EPA to induce expression of acoC only in the mutant strain.Key words: Pseudomonas putida, ethylphenylacetate esterase, acetoin cleaving system, acoC gene, dihydrolipoamide acetyl-transferase, E2 component, acoR gene.
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Ali NO, Bignon J, Rapoport G, Debarbouille M. Regulation of the acetoin catabolic pathway is controlled by sigma L in Bacillus subtilis. J Bacteriol 2001; 183:2497-504. [PMID: 11274109 PMCID: PMC95166 DOI: 10.1128/jb.183.8.2497-2504.2001] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2000] [Accepted: 01/23/2001] [Indexed: 11/20/2022] Open
Abstract
Bacillus subtilis grown in media containing amino acids or glucose secretes acetate, pyruvate, and large quantities of acetoin into the growth medium. Acetoin can be reused by the bacteria during stationary phase when other carbon sources have been depleted. The acoABCL operon encodes the E1alpha, E1beta, E2, and E3 subunits of the acetoin dehydrogenase complex in B. subtilis. Expression of this operon is induced by acetoin and repressed by glucose in the growth medium. The acoR gene is located downstream from the acoABCL operon and encodes a positive regulator which stimulates the transcription of the operon. The product of acoR has similarities to transcriptional activators of sigma 54-dependent promoters. The four genes of the operon are transcribed from a -12, -24 promoter, and transcription is abolished in acoR and sigL mutants. Deletion analysis showed that DNA sequences more than 85 bp upstream from the transcriptional start site are necessary for full induction of the operon. These upstream activating sequences are probably the targets of AcoR. Analysis of an acoR'-'lacZ strain of B. subtilis showed that the expression of acoR is not induced by acetoin and is repressed by the presence of glucose in the growth medium. Transcription of acoR is also negatively controlled by CcpA, a global regulator of carbon catabolite repression. A specific interaction of CcpA in the upstream region of acoR was demonstrated by DNase I footprinting experiments, suggesting that repression of transcription of acoR is mediated by the binding of CcpA to the promoter region of acoR.
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Affiliation(s)
- N O Ali
- Unité de Biochimie Microbienne, Institut Pasteur, URA 2172 du Centre National de la Recherche Scientifique, 75724 Paris Cedex 15, France
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Huang M, Oppermann-Sanio FB, Steinbüchel A. Biochemical and molecular characterization of the Bacillus subtilis acetoin catabolic pathway. J Bacteriol 1999; 181:3837-41. [PMID: 10368162 PMCID: PMC93865 DOI: 10.1128/jb.181.12.3837-3841.1999] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A recent study indicated that Bacillus subtilis catabolizes acetoin by enzymes encoded by the acu gene cluster (F. J. Grundy, D. A. Waters, T. Y. Takova, and T. M. Henkin, Mol. Microbiol. 10:259-271, 1993) that are completely different from those in the multicomponent acetoin dehydrogenase enzyme system (AoDH ES) encoded by aco gene clusters found before in all other bacteria capable of utilizing acetoin as the sole carbon source for growth. By hybridization with a DNA probe covering acoA and acoB of the AoDH ES from Clostridium magnum, genomic fragments from B. subtilis harboring acoA, acoB, acoC, acoL, and acoR homologous genes were identified, and some of them were functionally expressed in E. coli. Furthermore, acoA was inactivated in B. subtilis by disruptive mutagenesis; these mutants were impaired to express PPi-dependent AoDH E1 activity to remove acetoin from the medium and to grow with acetoin as the carbon source. Therefore, acetoin is catabolized in B. subtilis by the same mechanism as all other bacteria investigated so far, leaving the function of the previously described acu genes obscure.
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Affiliation(s)
- M Huang
- Institut für Mikrobiologie der Westfälischen Wilhelms-Universität Münster, D-48149 Münster, Germany
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A novel arylesterase active toward 7-aminocephalosporanic acid from Agrobacterium radiobacter IFO 12607: Nucleotide sequence, gene expression in Escherichia coli, and site-directed mutagenesis. ACTA ACUST UNITED AC 1998. [DOI: 10.1016/s0922-338x(97)86757-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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13
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Peng HL, Yang YH, Deng WL, Chang HY. Identification and characterization of acoK, a regulatory gene of the Klebsiella pneumoniae acoABCD operon. J Bacteriol 1997; 179:1497-504. [PMID: 9045805 PMCID: PMC178858 DOI: 10.1128/jb.179.5.1497-1504.1997] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
By using transposon insertional mutagenesis and deletion analyses, a recombinant clone containing the region upstream of the acoABCD operon of Klebsiella pneumoniae was found to be required for acetoin-inducible expression of the operon in Escherichia coli. The nucleotide sequence of the region was determined, and it displayed an open reading frame of 2,763 bp that is transcribed divergently to the acoABCD operon. This gene, designated acoK, is capable of encoding a protein with an overall 58.4% amino acid identity with MalT, the transcriptional activator of the E. coli maltose regulon. A conserved sequence for nucleotide binding at the N-terminal region, as well as a helix-turn-helix motif belonging to the LuxR family of transcriptional regulators at the C terminus, was also identified. Primer extension analysis identified two transcription initiation sites, S1 and S2, located 319 and 267 bp, respectively, upstream of the putative start codon of acoK. Several copies of NtrC recognition sequence [CAC-(N11 to N18)-GTG] were found in the promoter regions of both the acoK gene and the acoABCD operon. Acetoin-dependent expression of the acoABCD operon could be restored in the E. coli acoK mutants by supplying a plasmid carrying an intact acoK, suggesting a transactivating function of the gene product. The AcoK protein overproduced in E. coli was approximately 100 kDa, which is in good agreement with the molecular mass deduced from the nucleotide sequence. A specific DNA binding property and an ATPase activity of the purified AcoK were also demonstrated.
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Affiliation(s)
- H L Peng
- Department of Microbiology, Chang Gung College of Medicine and Technology, Kwei San, Tao Yuan, Taiwan
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14
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Zhu PP, Peterkofsky A. Sequence and organization of genes encoding enzymes involved in pyruvate metabolism in Mycoplasma capricolum. Protein Sci 1996; 5:1719-36. [PMID: 8844861 PMCID: PMC2143489 DOI: 10.1002/pro.5560050825] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The region of the genome of Mycoplasma capricolum upstream of the portion encompassing the genes for Enzymes I and IIAglc of the phosphoenolpyruvate:sugar phosphotransferase system (PTS) was cloned and sequenced. Examination of the sequence revealed open reading frames corresponding to numerous genes involved with the oxidation of pyruvate. The deduced gene organization is naox (encoding NADH oxidase)-lplA (encoding lipoate-protein ligase)-odpA (encoding pyruvate dehydrogenase EI alpha)-odpB (encoding pyruvate dehydrogenase EI beta)-odp2(encoding pyruvate dehydrogenase EII)-dldH (encoding dihydrolipoamide dehydrogenase)-pta (encoding phosphotransacetylase)-ack (encoding acetate kinase)-orfA (an unknown open reading frame)-kdtB-ptsI-crr. Analysis of the DNA sequence suggests that the naox and lplA genes are part of a single operon, odpA and odpB constitute an additional operon, odp2 and dldH a third operon, and pta and ack an additional transcription unit. Phylogenetic analyses of the protein products of the odpA and odpB genes indicate that they are most similar to the corresponding proteins from Mycoplasma genitalium, Acholeplasma laidlawii, and Gram-positive organisms. The product of the odp2 gene contains a single lipoyl domain, as is the case with the corresponding proteins from M. genitalium and numerous other organisms. An evolutionary tree places the M. capricolum odp2 gene product in close relationship to the corresponding proteins from A. laidlawii and M.genitalium. The dldH gene encodes an unusual form of dihydrolipoamide dehydrogenase that contains an aminoterminal extension corresponding to a lipoyl domain, a property shared by the corresponding proteins from Alcaligenes eutrophus and Clostridium magnum. Aside from that feature, the protein is related phylogenetically to the corresponding proteins from A. laidlawii and M. genitalium. The phosphotransacetylase from M. capricolum is related most closely to the corresponding protein from M. genitalium and is distinguished easily from the enzymes from Escherichia coli and Haemophilus influenzae by the absence of the characteristic amino-terminal extension. The acetate kinase from M. capricolum is related evolutionarily to the homologous enzyme from M. genitalium. Map position comparisons of genes encoding proteins involved with pyruvate metabolism show that, whereas all the genes are clustered in M. capricolum, they are scattered in M. genitalium.
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Affiliation(s)
- P P Zhu
- Laboratory of Biochemical Genetics, National Heart, Lung and Blood Institute, Bethesda, Maryland 20892, USA
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Hein S, Steinbüchel A. Alcaligenes eutrophus possesses a second pyruvate dehydrogenase (E1). EUROPEAN JOURNAL OF BIOCHEMISTRY 1996; 237:674-84. [PMID: 8647112 DOI: 10.1111/j.1432-1033.1996.0674p.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Two gene loci, which hybridized with pdhA, the structural gene of the E1 component of the Alcaligenes eutrophus pyruvate dehydrogenase complex [Hein, S. & Steinbüchel, A. (1994) J. Bacteriol. 176, 4394-4408], were identified on two nonrelated A. eutrophus chromosomal BamHI fragments by using a pdhA-specific DNA probe. These data indicated that A. eutrophus possesses, beside PdhA, two additional distinct pyruvate dehydrogenases (E1). A 6.8-kbp genomic BamHI fragment of A. eutrophus was cloned, and sequence analysis of a 3.896-kbp region revealed the structural gene pdhE (2.694 kbp) for a second pyruvate dehydrogenase (E1), which was not clustered with structural genes for other components of 2-oxo acid dehydrogenase complexes. The A. eutrophus pdhE gene product (898 amino acid residues) exhibited significant similarities to the E1 components of the pyruvate dehydrogenase complexes of A. eutrophus, Neisseria meningitidis, Escherichia coli and Azotobacter vinelandii, which are also composed of only one type of subunit. Heterologous expression of pdhE in the aceEF deletion mutant E. coli YYC202 was demonstrated by spectrometric detection of enzyme activities and by phenotypic complementation to acetate prototrophy. These complementation studies indicated that the E1 component of the A. eutrophus pyruvate dehydrogenase complex can be replaced by a functionally active pdhE gene product.
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Affiliation(s)
- S Hein
- Institut für Mikrobiologie, Westfälischen Wilhelms-Universität Münster, Germany
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Huang M, Oppermann FB, Steinbüchel A. Molecular characterization of the Pseudomonas putida 2,3-butanediol catabolic pathway. FEMS Microbiol Lett 1994; 124:141-50. [PMID: 7813883 DOI: 10.1111/j.1574-6968.1994.tb07276.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The 2,3-butanediol dehydrogenase and the acetoin-cleaving system were simultaneously induced in Pseudomonas putida PpG2 during growth on 2,3-butanediol and on acetoin. Hybridization with a DNA probe covering the genes for the E1 subunits of the Alcaligenes eutrophus acetoin cleaving system and nucleotide sequence analysis identified acoA (975 bp), acoB (1020 bp), apoC (1110 bp), acoX (1053 bp) and adh (1086 bp) in a 6.3-kb genomic region. The amino acid sequences deduced from acoA, acoB, and acoC for E1 alpha (M(r) 34639), E1 beta (M(r) 37268), and E2 (M(r) 39613) of the P. putida acetoin cleaving system exhibited striking similarities to those of the corresponding components of the A. eutrophus acetoin cleaving system and of the acetoin dehydrogenase enzyme system of Pelobacter carbinolicus and other bacteria. Strong sequence similarities of the adh translational product (2,3-butanediol dehydrogenase, M(r) 38361) were obtained to various alcohol dehydrogenases belonging to the zinc- and NAD(P)-dependent long-chain (group I) alcohol dehydrogenases. Expression of the P. putida ADH in Escherichia coli was demonstrated. The aco genes and adh constitute presumably one single operon which encodes all enzymes required for the conversion of 2,3-butanediol to central metabolites.
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Affiliation(s)
- M Huang
- Department of Biology, Scihuan Normal University, Chengdu, China
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