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Kümpel C, Grosser M, Tanabe TS, Dahl C. Fe/S proteins in microbial sulfur oxidation. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2024; 1871:119732. [PMID: 38631440 DOI: 10.1016/j.bbamcr.2024.119732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Revised: 02/26/2024] [Accepted: 04/04/2024] [Indexed: 04/19/2024]
Abstract
Iron-sulfur clusters serve as indispensable cofactors within proteins across all three domains of life. Fe/S clusters emerged early during the evolution of life on our planet and the biogeochemical cycle of sulfur is one of the most ancient and important element cycles. It is therefore no surprise that Fe/S proteins have crucial roles in the multiple steps of microbial sulfur metabolism. During dissimilatory sulfur oxidation in prokaryotes, Fe/S proteins not only serve as electron carriers in several steps, but also perform catalytic roles, including unprecedented reactions. Two cytoplasmic enzyme systems that oxidize sulfane sulfur to sulfite are of particular interest in this context: The rDsr pathway employs the reverse acting dissimilatory sulfite reductase rDsrAB as its key enzyme, while the sHdr pathway utilizes polypeptides resembling the HdrA, HdrB and HdrC subunits of heterodisulfide reductase from methanogenic archaea. Both pathways involve components predicted to bind unusual noncubane Fe/S clusters acting as catalysts for the formation of disulfide or sulfite. Mapping of Fe/S cluster machineries on the sulfur-oxidizing prokaryote tree reveals that ISC, SUF, MIS and SMS are all sufficient to meet the Fe/S cluster maturation requirements for operation of the sHdr or rDsr pathways. The sHdr pathway is dependent on lipoate-binding proteins that are assembled by a novel pathway, involving two Radical SAM proteins, namely LipS1 and LipS2. These proteins coordinate sulfur-donating auxiliary Fe/S clusters in atypical patterns by three cysteines and one histidine and act as lipoyl synthases by jointly inserting two sulfur atoms to an octanoyl residue. This article is part of a Special Issue entitled: Biogenesis and Function of Fe/S proteins.
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Affiliation(s)
- Carolin Kümpel
- Institut für Mikrobiologie & Biotechnologie, Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn, Germany
| | - Martina Grosser
- Institut für Mikrobiologie & Biotechnologie, Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn, Germany
| | - Tomohisa Sebastian Tanabe
- Institut für Mikrobiologie & Biotechnologie, Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn, Germany
| | - Christiane Dahl
- Institut für Mikrobiologie & Biotechnologie, Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn, Germany.
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2
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Cronan JE. Lipoic acid attachment to proteins: stimulating new developments. Microbiol Mol Biol Rev 2024:e0000524. [PMID: 38624243 DOI: 10.1128/mmbr.00005-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/17/2024] Open
Abstract
SUMMARYLipoic acid-modified proteins are essential for central metabolism and pathogenesis. In recent years, the Escherichia coli and Bacillus subtilis lipoyl assembly pathways have been modified and extended to archaea and diverse eukaryotes including humans. These extensions include a new pathway to insert the key sulfur atoms of lipoate, several new pathways of lipoate salvage, and a novel use of lipoic acid in sulfur-oxidizing bacteria. Other advances are the modification of E. coli LplA for studies of protein localization and protein-protein interactions in cell biology and in enzymatic removal of lipoate from lipoyl proteins. Finally, scenarios have been put forth for the evolution of lipoate assembly in archaea.
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Affiliation(s)
- John E Cronan
- Department of Microbiology, University of Illinois, Urbana, Illinois, USA
- Department of Biochemistry, University of Illinois, Urbana, Illinois, USA
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3
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Tanabe TS, Grosser M, Hahn L, Kümpel C, Hartenfels H, Vtulkin E, Flegler W, Dahl C. Identification of a novel lipoic acid biosynthesis pathway reveals the complex evolution of lipoate assembly in prokaryotes. PLoS Biol 2023; 21:e3002177. [PMID: 37368881 DOI: 10.1371/journal.pbio.3002177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Accepted: 05/31/2023] [Indexed: 06/29/2023] Open
Abstract
Lipoic acid is an essential biomolecule found in all domains of life and is involved in central carbon metabolism and dissimilatory sulfur oxidation. The machineries for lipoate assembly in mitochondria and chloroplasts of higher eukaryotes, as well as in the apicoplasts of some protozoa, are all of prokaryotic origin. Here, we provide experimental evidence for a novel lipoate assembly pathway in bacteria based on a sLpl(AB) lipoate:protein ligase, which attaches octanoate or lipoate to apo-proteins, and 2 radical SAM proteins, LipS1 and LipS2, which work together as lipoyl synthase and insert 2 sulfur atoms. Extensive homology searches combined with genomic context analyses allowed us to precisely distinguish between the new and established pathways and map them on the tree of life. This not only revealed a much wider distribution of lipoate biogenesis systems than expected, in particular, the novel sLpl(AB)-LipS1/S2 pathway, and indicated a highly modular nature of the enzymes involved, with unforeseen combinations, but also provided a new framework for the evolution of lipoate assembly. Our results show that dedicated machineries for both de novo lipoate biogenesis and scavenging from the environment were implemented early in evolution and that their distribution in the 2 prokaryotic domains was shaped by a complex network of horizontal gene transfers, acquisition of additional genes, fusions, and losses. Our large-scale phylogenetic analyses identify the bipartite archaeal LplAB ligase as the ancestor of the bacterial sLpl(AB) proteins, which were obtained by horizontal gene transfer. LipS1/S2 have a more complex evolutionary history with multiple of such events but probably also originated in the domain archaea.
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Affiliation(s)
- Tomohisa Sebastian Tanabe
- Institut für Mikrobiologie & Biotechnologie, Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn, Germany
| | - Martina Grosser
- Institut für Mikrobiologie & Biotechnologie, Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn, Germany
| | - Lea Hahn
- Institut für Mikrobiologie & Biotechnologie, Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn, Germany
| | - Carolin Kümpel
- Institut für Mikrobiologie & Biotechnologie, Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn, Germany
| | - Hanna Hartenfels
- Institut für Mikrobiologie & Biotechnologie, Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn, Germany
| | - Evelyn Vtulkin
- Institut für Mikrobiologie & Biotechnologie, Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn, Germany
| | - Wanda Flegler
- Institut für Mikrobiologie & Biotechnologie, Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn, Germany
| | - Christiane Dahl
- Institut für Mikrobiologie & Biotechnologie, Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn, Germany
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A Lipoate-Protein Ligase Is Required for De Novo Lipoyl-Protein Biosynthesis in the Hyperthermophilic Archaeon Thermococcus kodakarensis. Appl Environ Microbiol 2022; 88:e0064422. [PMID: 35736229 PMCID: PMC9275244 DOI: 10.1128/aem.00644-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Lipoic acid is an organosulfur cofactor essential for several key enzyme complexes in oxidative and one-carbon metabolism. It is covalently bound to the lipoyl domain of the E2 subunit in some 2-oxoacid dehydrogenase complexes and the H-protein in the glycine cleavage system. Lipoate-protein ligase (Lpl) is involved in the salvage of exogenous lipoate and attaches free lipoate to the E2 subunit or the H-protein in an ATP-dependent manner. In the hyperthermophilic archaeon Thermococcus kodakarensis, TK1234 and TK1908 are predicted to encode the N- and C-terminal regions of Lpl, respectively. TK1908 and TK1234 recombinant proteins form a heterodimer and together displayed significant ligase activity toward octanoate in addition to lipoate when a chemically synthesized octapeptide was used as the acceptor. The proteins also displayed activity toward other fatty acids, indicating broad fatty acid specificity. On the other hand, lipoyl synthase from T. kodakarensis only recognized octanoyl-peptide as a substrate. Examination of individual proteins indicated that the TK1908 protein alone was able to catalyze the ligase reaction although with a much lower activity. Gene disruption of TK1908 led to lipoate/serine auxotrophy, whereas TK1234 gene deletion did not. Acyl carrier protein homologs are not found on the archaeal genomes, and the TK1908/TK1234 protein complex did not utilize octanoyl-CoA, raising the possibility that the substrate of the ligase reaction is octanoic acid itself. Although Lpl has been considered as an enzyme involved in lipoate salvage, the results imply that in T. kodakarensis, the TK1908 and TK1234 proteins function in de novo lipoyl-protein biosynthesis. IMPORTANCE Based on previous studies in bacteria and eukaryotes, lipoate-protein ligases (Lpls) have been considered to be involved exclusively in lipoate salvage. The genetic analyses in this study on the lipoate-protein ligase in T. kodakarensis, however, suggest otherwise and that the enzyme is additionally involved in de novo protein lipoylation. We also provide biochemical evidence that the lipoate-protein ligase displays broad substrate specificity and is capable of ligating acyl groups of various chain-lengths to the peptide substrate. We show that this apparent ambiguity in Lpl is resolved by the strict substrate specificity of the lipoyl synthase LipS in this organism, which only recognizes octanoyl-peptide. The results provide relevant physiological insight into archaeal protein lipoylation.
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Lipoate protein ligase B primarily recognizes the C 8-phosphopantetheine arm of its donor substrate and weakly binds the acyl carrier protein. J Biol Chem 2022; 298:102203. [PMID: 35764173 PMCID: PMC9307952 DOI: 10.1016/j.jbc.2022.102203] [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: 04/28/2022] [Revised: 06/22/2022] [Accepted: 06/22/2022] [Indexed: 11/22/2022] Open
Abstract
Lipoic acid is a sulfur containing cofactor indispensable for the function of several metabolic enzymes. In microorganisms, lipoic acid can be salvaged from the surroundings by Lipoate protein ligase A (LplA), an ATP-dependent enzyme. Alternatively, it can be synthesized by the sequential actions of Lipoate protein ligase B (LipB) and Lipoyl synthase (LipA). LipB takes up the octanoyl chain from C8-acyl carrier protein (C8-ACP), a byproduct of the type II fatty acid synthesis pathway, and transfers it to a conserved lysine of the lipoyl domain of a dehydrogenase. However, the molecular basis of its substrate recognition is still not fully understood. Using E. coli LipB as a model enzyme, we show here that the octanoyl-transferase mainly recognizes the 4'-phosphopantetheine-tethered acyl-chain of its donor substrate and weakly binds the apo-acyl carrier protein. We demonstrate LipB can accept octanoate from its own ACP and noncognate ACPs, as well as C8-CoA. Furthermore, our 1H STD and 31P NMR studies demonstrate the binding of adenosine, as well as the phosphopantetheine arm of CoA to LipB, akin to binding to LplA. Finally, we show a conserved 71RGG73 loop, analogous to the lipoate binding loop of LplA, is required for full LipB activity. Collectively, our studies highlight commonalities between LipB and LplA in their mechanism of substrate recognition. This knowledge could be of significance in the treatment of mitochondrial fatty acid synthesis related disorders.
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Jin J, Chen H, Wang N, Zhu K, Liu H, Shi D, Xin J, Liu H. A Novel Lipoate-Protein Ligase, Mhp-LplJ, Is Required for Lipoic Acid Metabolism in Mycoplasma hyopneumoniae. Front Microbiol 2021; 11:631433. [PMID: 33584596 PMCID: PMC7873978 DOI: 10.3389/fmicb.2020.631433] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Accepted: 12/30/2020] [Indexed: 11/21/2022] Open
Abstract
Lipoic acid is a conserved cofactor necessary for the activation of several critical enzyme complexes in the aerobic metabolism of 2-oxoacids and one-carbon metabolism. Lipoate metabolism enzymes are key for lipoic acid biosynthesis and salvage. In this study, we found that Mycoplasma hyopneumoniae (M. hyopneumoniae) Mhp-Lpl, which had been previously shown to have lipoate-protein ligase activity against glycine cleavage system H protein (GcvH) in vitro, did not lipoylate the lipoate-dependent subunit of dihydrolipoamide dehydrogenase (PdhD). Further studies indicated that a new putative lipoate-protein ligase in M. hyopneumoniae, MHP_RS00640 (Mhp-LplJ), catalyzes free lipoic acid attachment to PdhD in vitro. In a model organism, Mhp-LplJ exhibited lipoate and octanoate ligase activities against PdhD. When the enzyme activity of Mhp-LplJ was disrupted by lipoic acid analogs, 8-bromooctanoic acid (8-BrO) and 6,8-dichlorooctanoate (6,8-diClO), M. hyopneumoniae growth was arrested in vitro. Taken together, these results indicate that Mhp-LplJ plays a vital role in lipoic acid metabolism of M. hyopneumoniae, which is of great significance to further understand the metabolism of M. hyopneumoniae and develop new antimicrobials against it.
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Affiliation(s)
- Jin Jin
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China.,Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northeast Agricultural University, Harbin, China
| | - Huan Chen
- Department of Biology, Guangdong Provincial Key Laboratory of Cell Microenvironment and Disease Research, Shenzhen Key Laboratory of Cell Microenvironment and SUSTech-HKU Joint Laboratories for Matrix Biology and Diseases, Southern University of Science and Technology, Shenzhen, China
| | - Ning Wang
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Kemeng Zhu
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Huanhuan Liu
- College of Life Science, Yangtze University, Kingchow, China
| | - Dongfang Shi
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northeast Agricultural University, Harbin, China
| | - Jiuqing Xin
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Henggui Liu
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
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7
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Cronan JE. Progress in the Enzymology of the Mitochondrial Diseases of Lipoic Acid Requiring Enzymes. Front Genet 2020; 11:510. [PMID: 32508887 PMCID: PMC7253636 DOI: 10.3389/fgene.2020.00510] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Accepted: 04/27/2020] [Indexed: 12/12/2022] Open
Abstract
Three human mitochondrial diseases that directly affect lipoic acid metabolism result from heterozygous missense and nonsense mutations in the LIAS, LIPT1, and LIPT2 genes. However, the functions of the proteins encoded by these genes in lipoic acid metabolism remained uncertain due to a lack of biochemical analysis at the enzyme level. An exception was the LIPT1 protein for which a perplexing property had been reported, a ligase lacking the ability to activate its substrate. This led to several models, some contradictory, to accommodate the role of LIPT1 protein activity in explaining the phenotypes of the afflicted neonatal patients. Recent evidence indicates that this LIPT1 protein activity is a misleading evolutionary artifact and that the physiological role of LIPT1 is in transfer of lipoic acid moieties from one protein to another. This and other new biochemical data now define a straightforward pathway that fully explains each of the human disorders specific to the assembly of lipoic acid on its cognate enzyme proteins.
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Affiliation(s)
- John E Cronan
- B103 Chemical and Life Sciences Laboratory, Departments of Microbiology and Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL, United States
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8
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Zhu K, Chen H, Jin J, Wang N, Ma G, Huang J, Feng Y, Xin J, Zhang H, Liu H. Functional Identification and Structural Analysis of a New Lipoate Protein Ligase in Mycoplasma hyopneumoniae. Front Cell Infect Microbiol 2020; 10:156. [PMID: 32373550 PMCID: PMC7186572 DOI: 10.3389/fcimb.2020.00156] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Accepted: 03/24/2020] [Indexed: 11/13/2022] Open
Abstract
Mycoplasma hyopneumoniae (M. hyopneumoniae) is the causative agent of pandemic pneumonia among pigs, namely, swine enzootic pneumonia. Although M. hyopneumoniae was first identified in 1965, little is known regarding its metabolic pathways, which might play a pivotal role during disease pathogenesis. Lipoate is an essential cofactor for enzymes important for central metabolism. However, the lipoate metabolism pathway in M. hyopneumoniae is definitely unclear. Here, we identified a novel gene, lpl, encoding a lipoate protein ligase in the genome of M. hyopneumoniae (Mhp-Lpl). This gene contains 1,032 base pairs and encodes a protein of 343 amino acids, which is between 7.5 and 36.09% identical to lipoate protein ligases (Lpls) of other species. Similar to its homologs in other species, Mhp-Lpl catalyzes the ATP-dependent activation of lipoate to lipoyl-AMP and the transfer of the activated lipoyl onto the lipoyl domains of M. hyopneumoniae GcvH (Mhp H) in vitro. Enzymatic and mutagenesis analysis indicate that residue K56 within the SKT sequence of Mhp H protein is the lipoyl moiety acceptor site. The three-dimensional structure showed typical lipoate protein ligase folding, with a large N-terminal domain and a small C-terminal domain. The large N-terminal domain is responsible for the full enzymatic activity of Mhp-Lpl. The identification and characterization of Mhp-Lpl will be beneficial to our understanding of M. hyopneumoniae metabolism. Summary Lipoic acid is an essential cofactor for the activation of some enzyme complexes involved in key metabolic processes. Lipoate protein ligases (Lpls) are responsible for the metabolism of lipoic acid. To date, little is known regarding the Lpls in M. hyopneumoniae. In this study, we identified a lipoate protein ligase of M. hyopneumoniae. We further analyzed the function, overall structure and ligand-binding site of this protein. The lipoate acceptor site on M. hyopneumoniae GcvH was also identified. Together, these findings reveal that Lpl exists in M. hyopneumoniae and will provide a basis for further exploration of the pathway of lipoic acid metabolism in M. hyopneumoniae.
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Affiliation(s)
- Kemeng Zhu
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, The Chinese Academy of Agricultural Sciences, Harbin, China
| | - Huan Chen
- Department of Biology, Guangdong Provincial Key Laboratory of Cell Microenvironment and Disease Research, Shenzhen Key Laboratory of Cell Microenvironment and SUSTech-HKU Joint Laboratories for Matrix Biology and Diseases, Southern University of Science and Technology, Shenzhen, China.,School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Jin Jin
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, The Chinese Academy of Agricultural Sciences, Harbin, China
| | - Ning Wang
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, The Chinese Academy of Agricultural Sciences, Harbin, China
| | - Guixing Ma
- Department of Biology, Guangdong Provincial Key Laboratory of Cell Microenvironment and Disease Research, Shenzhen Key Laboratory of Cell Microenvironment and SUSTech-HKU Joint Laboratories for Matrix Biology and Diseases, Southern University of Science and Technology, Shenzhen, China
| | - Jiandong Huang
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China.,Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Youjun Feng
- Department of Pathogen Biology and Microbiology, Zhejiang University School of Medicine, Hangzhou, China
| | - Jiuqing Xin
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, The Chinese Academy of Agricultural Sciences, Harbin, China
| | - Hongmin Zhang
- Department of Biology, Guangdong Provincial Key Laboratory of Cell Microenvironment and Disease Research, Shenzhen Key Laboratory of Cell Microenvironment and SUSTech-HKU Joint Laboratories for Matrix Biology and Diseases, Southern University of Science and Technology, Shenzhen, China
| | - Henggui Liu
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, The Chinese Academy of Agricultural Sciences, Harbin, China
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Cao X, Koch T, Steffens L, Finkensieper J, Zigann R, Cronan JE, Dahl C. Lipoate-binding proteins and specific lipoate-protein ligases in microbial sulfur oxidation reveal an atpyical role for an old cofactor. eLife 2018; 7:e37439. [PMID: 30004385 PMCID: PMC6067878 DOI: 10.7554/elife.37439] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Accepted: 07/12/2018] [Indexed: 01/02/2023] Open
Abstract
Many Bacteria and Archaea employ the heterodisulfide reductase (Hdr)-like sulfur oxidation pathway. The relevant genes are inevitably associated with genes encoding lipoate-binding proteins (LbpA). Here, deletion of the gene identified LbpA as an essential component of the Hdr-like sulfur-oxidizing system in the Alphaproteobacterium Hyphomicrobium denitrificans. Thus, a biological function was established for the universally conserved cofactor lipoate that is markedly different from its canonical roles in central metabolism. LbpAs likely function as sulfur-binding entities presenting substrate to different catalytic sites of the Hdr-like complex, similar to the substrate-channeling function of lipoate in carbon-metabolizing multienzyme complexes, for example pyruvate dehydrogenase. LbpAs serve a specific function in sulfur oxidation, cannot functionally replace the related GcvH protein in Bacillus subtilis and are not modified by the canonical E. coli and B. subtilis lipoyl attachment machineries. Instead, LplA-like lipoate-protein ligases encoded in or in immediate vicinity of hdr-lpbA gene clusters act specifically on these proteins.
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Affiliation(s)
- Xinyun Cao
- Department of BiochemistryUniversity of IllinoisUrbanaUnited States
| | - Tobias Koch
- Institut für Mikrobiologie and BiotechnologieRheinische Friedrich-Wilhelms-Universität BonnBonnGermany
| | - Lydia Steffens
- Institut für Mikrobiologie and BiotechnologieRheinische Friedrich-Wilhelms-Universität BonnBonnGermany
| | - Julia Finkensieper
- Institut für Mikrobiologie and BiotechnologieRheinische Friedrich-Wilhelms-Universität BonnBonnGermany
| | - Renate Zigann
- Institut für Mikrobiologie and BiotechnologieRheinische Friedrich-Wilhelms-Universität BonnBonnGermany
| | - John E Cronan
- Department of BiochemistryUniversity of IllinoisUrbanaUnited States
- Department of MicrobiologyUniversity of IllinoisUrbanaUnited States
| | - Christiane Dahl
- Institut für Mikrobiologie and BiotechnologieRheinische Friedrich-Wilhelms-Universität BonnBonnGermany
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Protein moonlighting elucidates the essential human pathway catalyzing lipoic acid assembly on its cognate enzymes. Proc Natl Acad Sci U S A 2018; 115:E7063-E7072. [PMID: 29987032 DOI: 10.1073/pnas.1805862115] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The lack of attachment of lipoic acid to its cognate enzyme proteins results in devastating human metabolic disorders. These mitochondrial disorders are evident soon after birth and generally result in early death. The mutations causing specific defects in lipoyl assembly map in three genes, LIAS, LIPT1, and LIPT2 Although physiological roles have been proposed for the encoded proteins, only the LIPT1 protein had been studied at the enzyme level. LIPT1 was reported to catalyze only the second partial reaction of the classical lipoate ligase mechanism. We report that the physiologically relevant LIPT1 enzyme activity is transfer of lipoyl moieties from the H protein of the glycine cleavage system to the E2 subunits of the 2-oxoacid dehydrogenases required for respiration (e.g., pyruvate dehydrogenase) and amino acid degradation. We also report that LIPT2 encodes an octanoyl transferase that initiates lipoyl group assembly. The human pathway is now biochemically defined.
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11
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Yadav U, Sundd M. Backbone chemical shift assignments of the glycine cleavage complex H protein of Escherichia coli. BIOMOLECULAR NMR ASSIGNMENTS 2018; 12:163-165. [PMID: 29335837 DOI: 10.1007/s12104-018-9801-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Accepted: 01/05/2018] [Indexed: 06/07/2023]
Abstract
Glycine cleavage complex H protein (GcvH) is one of the four components that form the glycine cleavage complex (GCS), essential for the synthesis of C1 (one-carbon units) for cell metabolism, by the oxidative cleavage of glycine. The activity of this complex is induced in the presence of exogenous glycine, and is repressed by purines. GCS, in cooperation with GCA (serine hydroxymethyltransferase) regulates the endogenous levels of glycine and C1 units in the cell. GcvH, the lipoamide containing component of the complex, plays an indispensable role in this reaction, as its prosthetic group shuttles between the active site of the three other components of the GCS complex sequentially. In environments rich in exogenous lipoic acid, GcvH is converted to lipoyl-GcvH by Lipoate protein ligase (LplA), by the salvage pathway. When exogenous lipoic acid is deficient, it is post-translationally modified to lipoyl-GcvH by the consecutive action of two enzymes, (a) Lipoate protein ligase B (LipB) and (b) Lipoyl synthase (LipA). Although, the crystal structure has been determined for Escherichia coli GcvH, no information exists for its interaction with LipB or LipA. Therefore, we plan to study its interactions with the aforementioned enzymes. As a first step, we have carried out the complete backbone chemical shift assignments of the E. coli glycine cleavage complex H protein in its apo-form, as well as its C8- intermediate.
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Affiliation(s)
- Usha Yadav
- National Institute of Immunology, Aruna Asaf Ali Marg, JNU Campus, New Delhi, 110 067, India
| | - Monica Sundd
- National Institute of Immunology, Aruna Asaf Ali Marg, JNU Campus, New Delhi, 110 067, India.
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12
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Expression and Activity of the BioH Esterase of Biotin Synthesis is Independent of Genome Context. Sci Rep 2017; 7:2141. [PMID: 28526858 PMCID: PMC5438404 DOI: 10.1038/s41598-017-01490-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Accepted: 03/28/2017] [Indexed: 01/15/2023] Open
Abstract
BioH is an α/β-hydrolase required for synthesis of the pimelate moiety of biotin in diverse bacteria. The bioH gene is found in different genomic contexts. In some cases (e.g., Escherichia coli) the gene is not located within a biotin synthetic operon and its transcription is not coregulated with the other biotin synthesis genes. In other genomes such as Pseudomonas aeruginosa the bioH gene is within a biotin synthesis operon and its transcription is coregulated with the other biotin operon genes. The esterases of pimelate moiety synthesis show remarkable genomic plasticity in that in some biotin operons bioH is replaced by other α/ß hydrolases of diverse sequence. The “wild card” nature of these enzymes led us to compare the paradigm “freestanding” E. coli BioH with the operon-encoded P. aeruginosa BioH. We hypothesized that the operon-encoded BioH might differ in its expression level and/or activity from the freestanding BioH gene. We report this is not the case. The two BioH proteins show remarkably similar hydrolase activities and substrate specificity. Moreover, Pseudomonas aeruginosa BioH is more highly expressed than E. coli BioH. Despite the enzymatic similarities of the two BioH proteins, bioinformatics analysis places the freestanding and operon-encoded BioH proteins into distinct clades.
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Assembly of Lipoic Acid on Its Cognate Enzymes: an Extraordinary and Essential Biosynthetic Pathway. Microbiol Mol Biol Rev 2016; 80:429-50. [PMID: 27074917 DOI: 10.1128/mmbr.00073-15] [Citation(s) in RCA: 86] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Although the structure of lipoic acid and its role in bacterial metabolism were clear over 50 years ago, it is only in the past decade that the pathways of biosynthesis of this universally conserved cofactor have become understood. Unlike most cofactors, lipoic acid must be covalently bound to its cognate enzyme proteins (the 2-oxoacid dehydrogenases and the glycine cleavage system) in order to function in central metabolism. Indeed, the cofactor is assembled on its cognate proteins rather than being assembled and subsequently attached as in the typical pathway, like that of biotin attachment. The first lipoate biosynthetic pathway determined was that of Escherichia coli, which utilizes two enzymes to form the active lipoylated protein from a fatty acid biosynthetic intermediate. Recently, a more complex pathway requiring four proteins was discovered in Bacillus subtilis, which is probably an evolutionary relic. This pathway requires the H protein of the glycine cleavage system of single-carbon metabolism to form active (lipoyl) 2-oxoacid dehydrogenases. The bacterial pathways inform the lipoate pathways of eukaryotic organisms. Plants use the E. coli pathway, whereas mammals and fungi probably use the B. subtilis pathway. The lipoate metabolism enzymes (except those of sulfur insertion) are members of PFAM family PF03099 (the cofactor transferase family). Although these enzymes share some sequence similarity, they catalyze three markedly distinct enzyme reactions, making the usual assignment of function based on alignments prone to frequent mistaken annotations. This state of affairs has possibly clouded the interpretation of one of the disorders of human lipoate metabolism.
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