1
|
Bannister KR, Prather KLJ. α-Substituted 3-hydroxy acid production from glucose in Escherichia coli. Metab Eng 2024; 86:124-134. [PMID: 39313110 DOI: 10.1016/j.ymben.2024.09.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2024] [Revised: 08/28/2024] [Accepted: 09/15/2024] [Indexed: 09/25/2024]
Abstract
Polyhydroxyalkanoates (PHAs) are renewably-derived, microbial polyesters composed of hydroxy acids (HAs). Demand for sustainable plastics alternatives, combined with the unfavorable thermal properties exhibited by some PHAs, motivates the discovery of novel PHA-based materials. Incorporation of α-substituted HAs yields thermostable PHAs; however, the reverse β-oxidation (rBOX) pathway, the canonical pathway for HA production, is unable to produce these monomers because it utilizes thiolases with narrow substrate specificity. Here, we present a thiolase-independent pathway to two α-substituted HAs, 3-hydroxyisobutyric acid (3HIB) and 3-hydroxy-2-methylbutyric acid (3H2MB). This pathway involves the conversion of glucose to various branched acyl-CoAs and ultimately to 3HIB or 3H2MB. As proof of concept, we engineered Escherichia coli for the specific production of 3HIB and 3H2MB from glucose at titers as high as 66 ± 5 mg/L and 290 ± 40 mg/L, respectively. Optimizing this pathway for 3H2MB production via a novel byproduct recycle increased titer by 60%. This work illustrates the utility of novel pathway design HA production leading to PHAs with industrially relevant properties.
Collapse
Affiliation(s)
- K'yal R Bannister
- Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA
| | - Kristala L J Prather
- Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA.
| |
Collapse
|
2
|
Helbich S, Barrantes I, Dos Anjos Borges LG, Pieper DH, Vainshtein Y, Sohn K, Engesser KH. The 2-methylpropene degradation pathway in Mycobacteriaceae family strains. Environ Microbiol 2023; 25:2163-2181. [PMID: 37321960 DOI: 10.1111/1462-2920.16449] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Accepted: 05/31/2023] [Indexed: 06/17/2023]
Abstract
Mycolicibacterium gadium IBE100 and Mycobacterium paragordonae IBE200 are aerobic, chemoorganoheterotrophic bacteria isolated from activated sludge from a wastewater treatment plant. They use 2-methylpropene (isobutene, 2-MP) as the sole source of carbon and energy. Here, we postulate a degradation pathway of 2-methylpropene derived from whole genome sequencing, differential expression analysis and peptide-mass fingerprinting. Key genes identified are coding for a 4-component soluble diiron monooxygenase with epoxidase activity, an epoxide hydrolase, and a 2-hydroxyisobutyryl-CoA mutase. In both strains, involved genes are arranged in clusters of 61.0 and 58.5 kbp, respectively, which also contain the genes coding for parts of the aerobic pathway of adenosylcobalamin synthesis. This vitamin is essential for the carbon rearrangement reaction catalysed by the mutase. These findings provide data for the identification of potential 2-methylpropene degraders.
Collapse
Affiliation(s)
- Steffen Helbich
- Institute for Sanitary Engineering, Water Quality and Solid Waste Management, University of Stuttgart, Stuttgart, Germany
| | - Israel Barrantes
- Microbial Interactions and Processes, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | | | - Dietmar H Pieper
- Microbial Interactions and Processes, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Yevhen Vainshtein
- Fraunhofer Institute for Interfacial Engineering and Biotechnology, Stuttgart, Germany
| | - Kai Sohn
- Fraunhofer Institute for Interfacial Engineering and Biotechnology, Stuttgart, Germany
| | - Karl-Heinrich Engesser
- Institute for Sanitary Engineering, Water Quality and Solid Waste Management, University of Stuttgart, Stuttgart, Germany
| |
Collapse
|
3
|
Vaccaro FA, Faber DA, Andree GA, Born DA, Kang G, Fonseca DR, Jost M, Drennan CL. Structural insight into G-protein chaperone-mediated maturation of a bacterial adenosylcobalamin-dependent mutase. J Biol Chem 2023; 299:105109. [PMID: 37517695 PMCID: PMC10481361 DOI: 10.1016/j.jbc.2023.105109] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 07/20/2023] [Accepted: 07/25/2023] [Indexed: 08/01/2023] Open
Abstract
G-protein metallochaperones are essential for the proper maturation of numerous metalloenzymes. The G-protein chaperone MMAA in humans (MeaB in bacteria) uses GTP hydrolysis to facilitate the delivery of adenosylcobalamin (AdoCbl) to AdoCbl-dependent methylmalonyl-CoA mutase, an essential metabolic enzyme. This G-protein chaperone also facilitates the removal of damaged cobalamin (Cbl) for repair. Although most chaperones are standalone proteins, isobutyryl-CoA mutase fused (IcmF) has a G-protein domain covalently attached to its target mutase. We previously showed that dimeric MeaB undergoes a 180° rotation to reach a state capable of GTP hydrolysis (an active G-protein state), in which so-called switch III residues of one protomer contact the G-nucleotide of the other protomer. However, it was unclear whether other G-protein chaperones also adopted this conformation. Here, we show that the G-protein domain in a fused system forms a similar active conformation, requiring IcmF oligomerization. IcmF oligomerizes both upon Cbl damage and in the presence of the nonhydrolyzable GTP analog, guanosine-5'-[(β,γ)-methyleno]triphosphate, forming supramolecular complexes observable by mass photometry and EM. Cryo-EM structural analysis reveals that the second protomer of the G-protein intermolecular dimer props open the mutase active site using residues of switch III as a wedge, allowing for AdoCbl insertion or damaged Cbl removal. With the series of structural snapshots now available, we now describe here the molecular basis of G-protein-assisted AdoCbl-dependent mutase maturation, explaining how GTP binding prepares a mutase for cofactor delivery and how GTP hydrolysis allows the mutase to capture the cofactor.
Collapse
Affiliation(s)
- Francesca A Vaccaro
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Daphne A Faber
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Gisele A Andree
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - David A Born
- Graduate Program in Biophysics, Harvard University, Cambridge, Massachusetts, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Gyunghoon Kang
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Dallas R Fonseca
- Amgen Scholar Program, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Marco Jost
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Catherine L Drennan
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA; Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.
| |
Collapse
|
4
|
Banerjee R, Gouda H, Pillay S. Redox-Linked Coordination Chemistry Directs Vitamin B 12 Trafficking. Acc Chem Res 2021; 54:2003-2013. [PMID: 33797888 DOI: 10.1021/acs.accounts.1c00083] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Metals are partners for an estimated one-third of the proteome and vary in complexity from mononuclear centers to organometallic cofactors. Vitamin B12 or cobalamin represents the epitome of this complexity and is the product of an assembly line comprising some 30 enzymes. Unable to biosynthesize cobalamin, mammals rely on dietary provision of this essential cofactor, which is needed by just two enzymes, one each in the cytoplasm (methionine synthase) and the mitochondrion (methylmalonyl-CoA mutase). Brilliant clinical genetics studies on patients with inborn errors of cobalamin metabolism spanning several decades had identified at least seven genetic loci in addition to the two encoding B12 enzymes. While cells are known to house a cadre of chaperones dedicated to metal trafficking pathways that contain metal reactivity and confer targeting specificity, the seemingly supernumerary chaperones in the B12 pathway had raised obvious questions as to the rationale for their existence.With the discovery of the genes underlying cobalamin disorders, our laboratory has been at the forefront of ascribing functions to B12 chaperones and elucidating the intricate redox-linked coordination chemistry and protein-linked cofactor conformational dynamics that orchestrate the processing and translocation of cargo along the trafficking pathway. These studies have uncovered novel chemistry that exploits the innate chemical versatility of alkylcobalamins, i.e., the ability to form and dismantle the cobalt-carbon bond using homolytic or heterolytic chemistry. In addition, they have revealed the practical utility of the dimethylbenzimidazole tail, an appendage unique to cobalamins and absent in the structural cousins, porphyrin, chlorin, and corphin, as an instrument for facilitating cofactor transfer between active sites.In this Account, we navigate the chemistry of the B12 trafficking pathway from its point of entry into cells, through lysosomes, and into the cytoplasm, where incoming cobalamin derivatives with a diversity of upper ligands are denuded by the β-ligand transferase activity of CblC to the common cob(II)alamin intermediate. The broad reaction and lax substrate specificity of CblC also enables conversion of cyanocobalamin (technically, vitamin B12, i.e., the form of the cofactor in one-a-day supplements), to cob(II)alamin. CblD then hitches up with CblC via a unique Co-sulfur bond to cob(II)alamin at a bifurcation point, leading to the cytoplasmic methylcobalamin or mitochondrial 5'-deoxyadenosylcobalamin branch. Mutations at loci upstream of the junction point typically affect both branches, leading to homocystinuria and methylmalonic aciduria, whereas mutations in downstream loci lead to one or the other disease. Elucidation of the biochemical penalties associated with individual mutations is providing molecular insights into the clinical data and, in some instances, identifying which cobalamin derivative(s) might be therapeutically beneficial.Our studies on B12 trafficking are revealing strategies for cofactor sequestration and mobilization from low- to high-affinity and low- to high-coordination-number sites, which in turn are regulated by protein dynamics that constructs ergonomic cofactor binding pockets. While these B12 lessons might be broadly relevant to other metal trafficking pathways, much remains to be learned. This Account concludes by identifying some of the major gaps and challenges that are needed to complete our understanding of B12 trafficking.
Collapse
Affiliation(s)
- Ruma Banerjee
- Department of Biological Chemistry, Michigan Medicine, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Harsha Gouda
- Department of Biological Chemistry, Michigan Medicine, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Shubhadra Pillay
- Department of Biological Chemistry, Michigan Medicine, University of Michigan, Ann Arbor, Michigan 48109, United States
| |
Collapse
|
5
|
Parise D, Teixeira Dornelles Parise M, Pinto Gomide AC, Figueira Aburjaile F, Bentes Kato R, Salgado-Albarrán M, Tauch A, Ariston de Carvalho Azevedo V, Baumbach J. The Transcriptional Regulatory Network of Corynebacterium pseudotuberculosis. Microorganisms 2021; 9:microorganisms9020415. [PMID: 33671149 PMCID: PMC7923171 DOI: 10.3390/microorganisms9020415] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 02/11/2021] [Accepted: 02/14/2021] [Indexed: 12/26/2022] Open
Abstract
Corynebacterium pseudotuberculosis is a Gram-positive, facultative intracellular, pathogenic bacterium that infects several different hosts, yielding serious economic losses in livestock farming. It causes several diseases including oedematous skin disease (OSD) in buffaloes, ulcerative lymphangitis (UL) in horses, and caseous lymphadenitis (CLA) in sheep, goats and humans. Despite its economic and medical-veterinary importance, our understanding concerning this organism’s transcriptional regulatory mechanisms is still limited. Here, we review the state of the art knowledge on transcriptional regulatory mechanisms of this pathogenic species, covering regulatory interactions mediated by two-component systems, transcription factors and sigma factors. Key transcriptional regulatory players involved in virulence and pathogenicity of C. pseudotuberculosis, such as the PhoPR system and DtxR, are in the focus of this review, as these regulators are promising targets for future vaccine design and drug development. We conclude that more experimental studies are needed to further understand the regulatory repertoire of this important zoonotic pathogen, and that regulators are promising targets for future vaccine design and drug development.
Collapse
Affiliation(s)
- Doglas Parise
- Chair of Experimental Bioinformatics, TUM School of Life Sciences, Technical University of Munich, 85354 Freising-Weihenstephan, Germany; (M.T.D.P.); (M.S.-A.); (J.B.)
- Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais 31270-901, Brazil; (A.C.P.G.); (R.B.K.); (V.A.d.C.A.)
- Correspondence: or
| | - Mariana Teixeira Dornelles Parise
- Chair of Experimental Bioinformatics, TUM School of Life Sciences, Technical University of Munich, 85354 Freising-Weihenstephan, Germany; (M.T.D.P.); (M.S.-A.); (J.B.)
- Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais 31270-901, Brazil; (A.C.P.G.); (R.B.K.); (V.A.d.C.A.)
| | - Anne Cybelle Pinto Gomide
- Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais 31270-901, Brazil; (A.C.P.G.); (R.B.K.); (V.A.d.C.A.)
| | | | - Rodrigo Bentes Kato
- Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais 31270-901, Brazil; (A.C.P.G.); (R.B.K.); (V.A.d.C.A.)
| | - Marisol Salgado-Albarrán
- Chair of Experimental Bioinformatics, TUM School of Life Sciences, Technical University of Munich, 85354 Freising-Weihenstephan, Germany; (M.T.D.P.); (M.S.-A.); (J.B.)
- Departamento de Ciencias Naturales, Universidad Autónoma Metropolitana Cuajimalpa, Mexico City 05348, Mexico
| | - Andreas Tauch
- Center for Biotechnology (CeBiTec), Bielefeld University, 33615 Bielefeld, Germany;
| | - Vasco Ariston de Carvalho Azevedo
- Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais 31270-901, Brazil; (A.C.P.G.); (R.B.K.); (V.A.d.C.A.)
| | - Jan Baumbach
- Chair of Experimental Bioinformatics, TUM School of Life Sciences, Technical University of Munich, 85354 Freising-Weihenstephan, Germany; (M.T.D.P.); (M.S.-A.); (J.B.)
- Computational BioMedicine lab, Institute of Mathematics and Computer Science, University of Southern Denmark, 5230 Odense, Denmark
- Chair of Computational Systems Biology, University of Hamburg, 22607 Hamburg, Germany
| |
Collapse
|
6
|
Liu B, Popp D, Müller N, Sträuber H, Harms H, Kleinsteuber S. Three Novel Clostridia Isolates Produce n-Caproate and iso-Butyrate from Lactate: Comparative Genomics of Chain-Elongating Bacteria. Microorganisms 2020; 8:microorganisms8121970. [PMID: 33322390 PMCID: PMC7764203 DOI: 10.3390/microorganisms8121970] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 12/08/2020] [Accepted: 12/09/2020] [Indexed: 02/07/2023] Open
Abstract
The platform chemicals n-caproate and iso-butyrate can be produced by anaerobic fermentation from agro-industrial residues in a process known as microbial chain elongation. Few lactate-consuming chain-elongating species have been isolated and knowledge on their shared genetic features is still limited. Recently we isolated three novel clostridial strains (BL-3, BL-4, and BL-6) that convert lactate to n-caproate and iso-butyrate. Here, we analyzed the genetic background of lactate-based chain elongation in these isolates and other chain-elongating species by comparative genomics. The three strains produced n-caproate, n-butyrate, iso-butyrate, and acetate from lactate, with the highest proportions of n-caproate (18%) for BL-6 and of iso-butyrate (23%) for BL-4 in batch cultivation at pH 5.5. They show high genomic heterogeneity and a relatively small core-genome size. The genomes contain highly conserved genes involved in lactate oxidation, reverse β-oxidation, hydrogen formation and either of two types of energy conservation systems (Rnf and Ech). Including genomes of another eleven experimentally validated chain-elongating strains, we found that the chain elongation-specific core-genome encodes the pathways for reverse β-oxidation, hydrogen formation and energy conservation, while displaying substantial genome heterogeneity. Metabolic features of these isolates are important for biotechnological applications in n-caproate and iso-butyrate production.
Collapse
Affiliation(s)
- Bin Liu
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research—UFZ, 04318 Leipzig, Germany; (B.L.); (D.P.); (H.S.); (H.H.)
| | - Denny Popp
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research—UFZ, 04318 Leipzig, Germany; (B.L.); (D.P.); (H.S.); (H.H.)
| | - Nicolai Müller
- Department of Biology, University of Konstanz, 78457 Konstanz, Germany;
| | - Heike Sträuber
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research—UFZ, 04318 Leipzig, Germany; (B.L.); (D.P.); (H.S.); (H.H.)
| | - Hauke Harms
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research—UFZ, 04318 Leipzig, Germany; (B.L.); (D.P.); (H.S.); (H.H.)
| | - Sabine Kleinsteuber
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research—UFZ, 04318 Leipzig, Germany; (B.L.); (D.P.); (H.S.); (H.H.)
- Correspondence: ; Tel.: +49-341-235-1325
| |
Collapse
|
7
|
Grosjean N, Blaby-Haas CE. Leveraging computational genomics to understand the molecular basis of metal homeostasis. THE NEW PHYTOLOGIST 2020; 228:1472-1489. [PMID: 32696981 DOI: 10.1111/nph.16820] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Accepted: 07/03/2020] [Indexed: 06/11/2023]
Abstract
Genome-based data is helping to reveal the diverse strategies plants and algae use to maintain metal homeostasis. In addition to acquisition, distribution and storage of metals, acclimating to feast or famine can involve a wealth of genes that we are just now starting to understand. The fast-paced acquisition of genome-based data, however, is far outpacing our ability to experimentally characterize protein function. Computational genomic approaches are needed to fill the gap between what is known and unknown. To avoid misconstruing bioinformatically derived data, which is the root cause of the inaccurate functional annotations that plague databases, functional inferences from diverse sources and contextualization of that evidence with a robust understanding of protein family evolution is needed. Phylogenomic- and comparative-genomic-based studies can aid in the interpretation of experimental data or provide a spark for the discovery of a new function. These analyses not only lead to novel insight into a target protein's function but can generate thought-provoking insights across protein families.
Collapse
Affiliation(s)
- Nicolas Grosjean
- Biology Department, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | | |
Collapse
|
8
|
Ruetz M, Campanello GC, McDevitt L, Yokom AL, Yadav PK, Watkins D, Rosenblatt DS, Ohi MD, Southworth DR, Banerjee R. Allosteric Regulation of Oligomerization by a B 12 Trafficking G-Protein Is Corrupted in Methylmalonic Aciduria. Cell Chem Biol 2019; 26:960-969.e4. [PMID: 31056463 DOI: 10.1016/j.chembiol.2019.03.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2018] [Revised: 03/07/2019] [Accepted: 03/25/2019] [Indexed: 10/26/2022]
Abstract
Allosteric regulation of methylmalonyl-CoA mutase (MCM) by the G-protein chaperone CblA is transduced via three "switch" elements that gate the movement of the B12 cofactor to and from MCM. Mutations in CblA and MCM cause hereditary methylmalonic aciduria. Unlike the bacterial orthologs used previously to model disease-causing mutations, human MCM and CblA exhibit a complex pattern of regulation that involves interconverting oligomers, which are differentially sensitive to the presence of GTP versus GDP. Patient mutations in the switch III region of CblA perturb the nucleotide-sensitive distribution of the oligomeric complexes with MCM, leading to loss of regulated movement of B12 to and/or from MCM and explain the molecular mechanism of the resulting disease.
Collapse
Affiliation(s)
- Markus Ruetz
- Department of Biological Chemistry, University of Michigan Medical Center, Ann Arbor, MI, USA
| | - Gregory C Campanello
- Department of Biological Chemistry, University of Michigan Medical Center, Ann Arbor, MI, USA
| | - Liam McDevitt
- Department of Biological Chemistry, University of Michigan Medical Center, Ann Arbor, MI, USA
| | - Adam L Yokom
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA
| | - Pramod K Yadav
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA
| | - David Watkins
- Department of Human Genetics, McGill University, Montreal, QC H3A 1B1, Canada
| | - David S Rosenblatt
- Department of Human Genetics, McGill University, Montreal, QC H3A 1B1, Canada
| | - Melanie D Ohi
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA
| | - Daniel R Southworth
- Department of Biochemistry and Biophysics, Institute for Neurodegenerative Diseases, University of California-San Francisco, San Francisco, CA 94158, USA
| | - Ruma Banerjee
- Department of Biological Chemistry, University of Michigan Medical Center, Ann Arbor, MI, USA.
| |
Collapse
|
9
|
Black WB, Zhang L, Kamoku C, Liao JC, Li H. Rearrangement of Coenzyme A-Acylated Carbon Chain Enables Synthesis of Isobutanol via a Novel Pathway in Ralstonia eutropha. ACS Synth Biol 2018; 7:794-800. [PMID: 29429336 DOI: 10.1021/acssynbio.7b00409] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Coenzyme A (CoA)-dependent pathways have been explored extensively for the biosynthesis of fuels and chemicals. While CoA-dependent mechanisms are widely used to elongate carbon chains in a linear fashion, branch-making chemistry has not been incorporated. In this study, we demonstrated the production of isobutanol, a branched-chain alcohol that can be used as a gasoline substitute, using a novel CoA-dependent pathway in recombinant Ralstonia eutropha H16. The designed pathway is constituted of three modules: chain elongation, rearrangement, and modification. We first integrated and optimized the chain elongation and modification modules, and we achieved the production of ∼200 mg/L n-butanol from fructose or ∼30 mg/L from formate by engineered R. eutropha. Subsequently, we incorporated the rearrangement module, which features a previously uncharacterized, native isobutyryl-CoA mutase in R. eutropha. The engineered strain produced ∼30 mg/L isobutanol from fructose. The carbon skeleton rearrangement chemistry demonstrated here may be used to expand the range of the chemicals accessible with CoA-dependent pathways.
Collapse
Affiliation(s)
- William B. Black
- Department of Chemical Engineering and Materials Science, University of California, Irvine, Irvine, California 90697, United States
| | - Linyue Zhang
- Department of Chemical Engineering and Materials Science, University of California, Irvine, Irvine, California 90697, United States
| | - Cody Kamoku
- Department of Chemical Engineering and Materials Science, University of California, Irvine, Irvine, California 90697, United States
| | - James C. Liao
- Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, Los Angeles, California 90095, United States
| | - Han Li
- Department of Chemical Engineering and Materials Science, University of California, Irvine, Irvine, California 90697, United States
| |
Collapse
|
10
|
Campanello GC, Lofgren M, Yokom AL, Southworth DR, Banerjee R. Switch I-dependent allosteric signaling in a G-protein chaperone-B 12 enzyme complex. J Biol Chem 2017; 292:17617-17625. [PMID: 28882898 DOI: 10.1074/jbc.m117.786095] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Revised: 08/14/2017] [Indexed: 11/06/2022] Open
Abstract
G-proteins regulate various processes ranging from DNA replication and protein synthesis to cytoskeletal dynamics and cofactor assimilation and serve as models for uncovering strategies deployed for allosteric signal transduction. MeaB is a multifunctional G-protein chaperone, which gates loading of the active 5'-deoxyadenosylcobalamin cofactor onto methylmalonyl-CoA mutase (MCM) and precludes loading of inactive cofactor forms. MeaB also safeguards MCM, which uses radical chemistry, against inactivation and rescues MCM inactivated during catalytic turnover by using the GTP-binding energy to offload inactive cofactor. The conserved switch I and II signaling motifs used by G-proteins are predicted to mediate allosteric regulation in response to nucleotide binding and hydrolysis in MeaB. Herein, we targeted conserved residues in the MeaB switch I motif to interrogate the function of this loop. Unexpectedly, the switch I mutations had only modest effects on GTP binding and on GTPase activity and did not perturb stability of the MCM-MeaB complex. However, these mutations disrupted multiple MeaB chaperone functions, including cofactor editing, loading, and offloading. Hence, although residues in the switch I motif are not essential for catalysis, they are important for allosteric regulation. Furthermore, single-particle EM analysis revealed, for the first time, the overall architecture of the MCM-MeaB complex, which exhibits a 2:1 stoichiometry. These EM studies also demonstrate that the complex exhibits considerable conformational flexibility. In conclusion, the switch I element does not significantly stabilize the MCM-MeaB complex or influence the affinity of MeaB for GTP but is required for transducing signals between MeaB and MCM.
Collapse
Affiliation(s)
- Gregory C Campanello
- From the Departments of Biological Chemistry, University of Michigan Medical Center, and
| | - Michael Lofgren
- From the Departments of Biological Chemistry, University of Michigan Medical Center, and
| | - Adam L Yokom
- From the Departments of Biological Chemistry, University of Michigan Medical Center, and.,the Department of Biological Chemistry and.,the Graduate Program in Chemical Biology, Life Sciences Institute, University of Michigan Medical Center, Ann Arbor, Michigan 48109-0600
| | - Daniel R Southworth
- From the Departments of Biological Chemistry, University of Michigan Medical Center, and.,the Department of Biological Chemistry and
| | - Ruma Banerjee
- From the Departments of Biological Chemistry, University of Michigan Medical Center, and
| |
Collapse
|
11
|
Li Z, Kitanishi K, Twahir UT, Cracan V, Chapman D, Warncke K, Banerjee R. Cofactor Editing by the G-protein Metallochaperone Domain Regulates the Radical B 12 Enzyme IcmF. J Biol Chem 2017; 292:3977-3987. [PMID: 28130442 DOI: 10.1074/jbc.m117.775957] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Indexed: 11/06/2022] Open
Abstract
IcmF is a 5'-deoxyadenosylcobalamin (AdoCbl)-dependent enzyme that catalyzes the carbon skeleton rearrangement of isobutyryl-CoA to butyryl-CoA. It is a bifunctional protein resulting from the fusion of a G-protein chaperone with GTPase activity and the cofactor- and substrate-binding mutase domains with isomerase activity. IcmF is prone to inactivation during catalytic turnover, thus setting up its dependence on a cofactor repair system. Herein, we demonstrate that the GTPase activity of IcmF powers the ejection of the inactive cob(II)alamin cofactor and requires the presence of an acceptor protein, adenosyltransferase, for receiving it. Adenosyltransferase in turn converts cob(II)alamin to AdoCbl in the presence of ATP and a reductant. The repaired cofactor is then reloaded onto IcmF in a GTPase-gated step. The mechanistic details of cofactor loading and offloading from the AdoCbl-dependent IcmF are distinct from those of the better characterized and homologous methylmalonyl-CoA mutase/G-protein chaperone system.
Collapse
Affiliation(s)
- Zhu Li
- From the Department of Biological Chemistry, University of Michigan Medical Center, Ann Arbor, Michigan 48109-0600 and
| | - Kenichi Kitanishi
- From the Department of Biological Chemistry, University of Michigan Medical Center, Ann Arbor, Michigan 48109-0600 and
| | - Umar T Twahir
- the Department of Physics, Emory University, Atlanta, Georgia 30322-2430
| | - Valentin Cracan
- From the Department of Biological Chemistry, University of Michigan Medical Center, Ann Arbor, Michigan 48109-0600 and
| | - Derrell Chapman
- From the Department of Biological Chemistry, University of Michigan Medical Center, Ann Arbor, Michigan 48109-0600 and
| | - Kurt Warncke
- the Department of Physics, Emory University, Atlanta, Georgia 30322-2430
| | - Ruma Banerjee
- From the Department of Biological Chemistry, University of Michigan Medical Center, Ann Arbor, Michigan 48109-0600 and
| |
Collapse
|
12
|
Jost M, Born DA, Cracan V, Banerjee R, Drennan CL. Structural Basis for Substrate Specificity in Adenosylcobalamin-dependent Isobutyryl-CoA Mutase and Related Acyl-CoA Mutases. J Biol Chem 2015; 290:26882-26898. [PMID: 26318610 DOI: 10.1074/jbc.m115.676890] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Indexed: 11/06/2022] Open
Abstract
Acyl-CoA mutases are a growing class of adenosylcobalamin-dependent radical enzymes that perform challenging carbon skeleton rearrangements in primary and secondary metabolism. Members of this class of enzymes must precisely control substrate positioning to prevent oxidative interception of radical intermediates during catalysis. Our understanding of substrate specificity and catalysis in acyl-CoA mutases, however, is incomplete. Here, we present crystal structures of IcmF, a natural fusion protein variant of isobutyryl-CoA mutase, in complex with the adenosylcobalamin cofactor and four different acyl-CoA substrates. These structures demonstrate how the active site is designed to accommodate the aliphatic acyl chains of each substrate. The structures suggest that a conformational change of the 5'-deoxyadenosyl group from C2'-endo to C3'-endo could contribute to initiation of catalysis. Furthermore, detailed bioinformatic analyses guided by our structural findings identify critical determinants of acyl-CoA mutase substrate specificity and predict new acyl-CoA mutase-catalyzed reactions. These results expand our understanding of the substrate specificity and the catalytic scope of acyl-CoA mutases and could benefit engineering efforts for biotechnological applications ranging from production of biofuels and commercial products to hydrocarbon remediation.
Collapse
Affiliation(s)
- Marco Jost
- Departments of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
| | - David A Born
- Departments of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139; the Graduate Program in Biophysics, Harvard University, Cambridge, Massachusetts 02138
| | - Valentin Cracan
- Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan 48109-0600
| | - Ruma Banerjee
- Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan 48109-0600
| | - Catherine L Drennan
- Departments of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139; Departments of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139; Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139,.
| |
Collapse
|
13
|
Shibata N, Toraya T. Molecular architectures and functions of radical enzymes and their (re)activating proteins. J Biochem 2015; 158:271-92. [PMID: 26261050 DOI: 10.1093/jb/mvv078] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Accepted: 07/22/2015] [Indexed: 02/07/2023] Open
Abstract
Certain proteins utilize the high reactivity of radicals for catalysing chemically challenging reactions. These proteins contain or form a radical and therefore named 'radical enzymes'. Radicals are introduced by enzymes themselves or by (re)activating proteins called (re)activases. The X-ray structures of radical enzymes and their (re)activases revealed some structural features of these molecular apparatuses which solved common enigmas of radical enzymes—i.e. how the enzymes form or introduce radicals at the active sites, how they use the high reactivity of radicals for catalysis, how they suppress undesired side reactions of highly reactive radicals and how they are (re)activated when inactivated by extinction of radicals. This review highlights molecular architectures of radical B12 enzymes, radical SAM enzymes, tyrosyl radical enzymes, glycyl radical enzymes and their (re)activating proteins that support their functions. For generalization, comparisons of the recently reported structures of radical enzymes with those of canonical radical enzymes are summarized here.
Collapse
Affiliation(s)
- Naoki Shibata
- Department of Life Science, Graduate School of Life Science, University of Hyogo, 3-2-1 Koto, Kamigori-cho, Ako-gun, Hyogo 678-1297, Japan and
| | - Tetsuo Toraya
- Department of Bioscience and Biotechnology, Graduate School of Natural Science and Technology, Okayama University, Tsushima-naka, Kita-ku, Okayama 700-8530, Japan
| |
Collapse
|
14
|
Kitanishi K, Cracan V, Banerjee R. Engineered and Native Coenzyme B12-dependent Isovaleryl-CoA/Pivalyl-CoA Mutase. J Biol Chem 2015; 290:20466-76. [PMID: 26134562 DOI: 10.1074/jbc.m115.646299] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Indexed: 11/06/2022] Open
Abstract
Adenosylcobalamin-dependent isomerases catalyze carbon skeleton rearrangements using radical chemistry. We have recently demonstrated that an isobutyryl-CoA mutase variant, IcmF, a member of this enzyme family that catalyzes the interconversion of isobutyryl-CoA and n-butyryl-CoA also catalyzes the interconversion between isovaleryl-CoA and pivalyl-CoA, albeit with low efficiency and high susceptibility to inactivation. Given the biotechnological potential of the isovaleryl-CoA/pivalyl-CoA mutase (PCM) reaction, we initially attempted to engineer IcmF to be a more proficient PCM by targeting two active site residues predicted based on sequence alignments and crystal structures, to be key to substrate selectivity. Of the eight mutants tested, the F598A mutation was the most robust, resulting in an ∼17-fold increase in the catalytic efficiency of the PCM activity and a concomitant ∼240-fold decrease in the isobutyryl-CoA mutase activity compared with wild-type IcmF. Hence, mutation of a single residue in IcmF tuned substrate specificity yielding an ∼4000-fold increase in the specificity for an unnatural substrate. However, the F598A mutant was even more susceptible to inactivation than wild-type IcmF. To circumvent this limitation, we used bioinformatics analysis to identify an authentic PCM in genomic databases. Cloning and expression of the putative AdoCbl-dependent PCM with an α2β2 heterotetrameric organization similar to that of isobutyryl-CoA mutase and a recently characterized archaeal methylmalonyl-CoA mutase, allowed demonstration of its robust PCM activity. To simplify kinetic analysis and handling, a variant PCM-F was generated in which the αβ subunits were fused into a single polypeptide via a short 11-amino acid linker. The fusion protein, PCM-F, retained high PCM activity and like PCM, was resistant to inactivation. Neither PCM nor PCM-F displayed detectable isobutyryl-CoA mutase activity, demonstrating that PCM represents a novel 5'-deoxyadenosylcobalamin-dependent acyl-CoA mutase. The newly discovered PCM and the derivative PCM-F, have potential applications in bioremediation of pivalic acid found in sludge, in stereospecific synthesis of C5 carboxylic acids and alcohols, and in the production of potential commodity and specialty chemicals.
Collapse
Affiliation(s)
- Kenichi Kitanishi
- From the Department of Biological Chemistry, University of Michigan Medical Center, Ann Arbor, Michigan 48109-0600
| | - Valentin Cracan
- From the Department of Biological Chemistry, University of Michigan Medical Center, Ann Arbor, Michigan 48109-0600
| | - Ruma Banerjee
- From the Department of Biological Chemistry, University of Michigan Medical Center, Ann Arbor, Michigan 48109-0600
| |
Collapse
|
15
|
Thermophilic Coenzyme B12-Dependent Acyl Coenzyme A (CoA) Mutase from Kyrpidia tusciae DSM 2912 Preferentially Catalyzes Isomerization of (R)-3-Hydroxybutyryl-CoA and 2-Hydroxyisobutyryl-CoA. Appl Environ Microbiol 2015; 81:4564-72. [PMID: 25911482 DOI: 10.1128/aem.00716-15] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Accepted: 04/21/2015] [Indexed: 01/21/2023] Open
Abstract
The recent discovery of a coenzyme B12-dependent acyl-coenzyme A (acyl-CoA) mutase isomerizing 3-hydroxybutyryl- and 2-hydroxyisobutyryl-CoA in the mesophilic bacterium Aquincola tertiaricarbonis L108 (N. Yaneva, J. Schuster, F. Schäfer, V. Lede, D. Przybylski, T. Paproth, H. Harms, R. H. Müller, and T. Rohwerder, J Biol Chem 287:15502-15511, 2012, http://dx.doi.org/10.1074/jbc.M111.314690) could pave the way for a complete biosynthesis route to the building block chemical 2-hydroxyisobutyric acid from renewable carbon. However, the enzyme catalyzes only the conversion of the stereoisomer (S)-3-hydroxybutyryl-CoA at reasonable rates, which seriously hampers an efficient combination of mutase and well-established bacterial poly-(R)-3-hydroxybutyrate (PHB) overflow metabolism. Here, we characterize a new 2-hydroxyisobutyryl-CoA mutase found in the thermophilic knallgas bacterium Kyrpidia tusciae DSM 2912. Reconstituted mutase subunits revealed highest activity at 55°C. Surprisingly, already at 30°C, isomerization of (R)-3-hydroxybutyryl-CoA was about 7,000 times more efficient than with the mutase from strain L108. The most striking structural difference between the two mutases, likely determining stereospecificity, is a replacement of active-site residue Asp found in strain L108 at position 117 with Val in the enzyme from strain DSM 2912, resulting in a reversed polarity at this binding site. Overall sequence comparison indicates that both enzymes descended from different prokaryotic thermophilic methylmalonyl-CoA mutases. Concomitant expression of PHB enzymes delivering (R)-3-hydroxybutyryl-CoA (beta-ketothiolase PhaA and acetoacetyl-CoA reductase PhaB from Cupriavidus necator) with the new mutase in Escherichia coli JM109 and BL21 strains incubated on gluconic acid at 37°C led to the production of 2-hydroxyisobutyric acid at maximal titers of 0.7 mM. Measures to improve production in E. coli, such as coexpression of the chaperone MeaH and repression of thioesterase II, are discussed.
Collapse
|
16
|
Kurteva-Yaneva N, Zahn M, Weichler MT, Starke R, Harms H, Müller RH, Sträter N, Rohwerder T. Structural basis of the stereospecificity of bacterial B12-dependent 2-hydroxyisobutyryl-CoA mutase. J Biol Chem 2015; 290:9727-37. [PMID: 25720495 DOI: 10.1074/jbc.m115.645689] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Indexed: 11/06/2022] Open
Abstract
Bacterial coenzyme B12-dependent 2-hydroxyisobutyryl-CoA mutase (HCM) is a radical enzyme catalyzing the stereospecific interconversion of (S)-3-hydroxybutyryl- and 2-hydroxyisobutyryl-CoA. It consists of two subunits, HcmA and HcmB. To characterize the determinants of substrate specificity, we have analyzed the crystal structure of HCM from Aquincola tertiaricarbonis in complex with coenzyme B12 and the substrates (S)-3-hydroxybutyryl- and 2-hydroxyisobutyryl-CoA in alternative binding. When compared with the well studied structure of bacterial and mitochondrial B12-dependent methylmalonyl-CoA mutase (MCM), HCM has a highly conserved domain architecture. However, inspection of the substrate binding site identified amino acid residues not present in MCM, namely HcmA Ile(A90) and Asp(A117). Asp(A117) determines the orientation of the hydroxyl group of the acyl-CoA esters by H-bond formation, thus determining stereospecificity of catalysis. Accordingly, HcmA D117A and D117V mutations resulted in significantly increased activity toward (R)-3-hydroxybutyryl-CoA. Besides interconversion of hydroxylated acyl-CoA esters, wild-type HCM as well as HcmA I90V and I90A mutant enzymes could also isomerize pivalyl- and isovaleryl-CoA, albeit at >10 times lower rates than the favorite substrate (S)-3-hydroxybutyryl-CoA. The nonconservative mutation HcmA D117V, however, resulted in an enzyme showing high activity toward pivalyl-CoA. Structural requirements for binding and isomerization of highly branched acyl-CoA substrates such as 2-hydroxyisobutyryl- and pivalyl-CoA, possessing tertiary and quaternary carbon atoms, respectively, are discussed.
Collapse
Affiliation(s)
- Nadya Kurteva-Yaneva
- From the Department of Environmental Microbiology, Helmholtz Centre for Environmental Research (UFZ), 04318 Leipzig and
| | - Michael Zahn
- the Center for Biotechnology and Biomedicine, Institute of Bioanalytical Chemistry, Faculty of Chemistry and Mineralogy, University of Leipzig, 04103 Leipzig, Germany
| | - M-Teresa Weichler
- From the Department of Environmental Microbiology, Helmholtz Centre for Environmental Research (UFZ), 04318 Leipzig and
| | - Robert Starke
- From the Department of Environmental Microbiology, Helmholtz Centre for Environmental Research (UFZ), 04318 Leipzig and
| | - Hauke Harms
- From the Department of Environmental Microbiology, Helmholtz Centre for Environmental Research (UFZ), 04318 Leipzig and
| | - Roland H Müller
- From the Department of Environmental Microbiology, Helmholtz Centre for Environmental Research (UFZ), 04318 Leipzig and
| | - Norbert Sträter
- the Center for Biotechnology and Biomedicine, Institute of Bioanalytical Chemistry, Faculty of Chemistry and Mineralogy, University of Leipzig, 04103 Leipzig, Germany
| | - Thore Rohwerder
- From the Department of Environmental Microbiology, Helmholtz Centre for Environmental Research (UFZ), 04318 Leipzig and
| |
Collapse
|
17
|
Visualization of a radical B12 enzyme with its G-protein chaperone. Proc Natl Acad Sci U S A 2015; 112:2419-24. [PMID: 25675500 DOI: 10.1073/pnas.1419582112] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
G-protein metallochaperones ensure fidelity during cofactor assembly for a variety of metalloproteins, including adenosylcobalamin (AdoCbl)-dependent methylmalonyl-CoA mutase and hydrogenase, and thus have both medical and biofuel development applications. Here, we present crystal structures of IcmF, a natural fusion protein of AdoCbl-dependent isobutyryl-CoA mutase and its corresponding G-protein chaperone, which reveal the molecular architecture of a G-protein metallochaperone in complex with its target protein. These structures show that conserved G-protein elements become ordered upon target protein association, creating the molecular pathways that both sense and report on the cofactor loading state. Structures determined of both apo- and holo-forms of IcmF depict both open and closed enzyme states, in which the cofactor-binding domain is alternatively positioned for cofactor loading and for catalysis. Notably, the G protein moves as a unit with the cofactor-binding domain, providing a visualization of how a chaperone assists in the sequestering of a precious cofactor inside an enzyme active site.
Collapse
|
18
|
Retro-biosynthetic screening of a modular pathway design achieves selective route for microbial synthesis of 4-methyl-pentanol. Nat Commun 2014; 5:5031. [PMID: 25248664 DOI: 10.1038/ncomms6031] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Accepted: 08/19/2014] [Indexed: 12/20/2022] Open
Abstract
Increasingly complex metabolic pathways have been engineered by modifying natural pathways and establishing de novo pathways with enzymes from a variety of organisms. Here we apply retro-biosynthetic screening to a modular pathway design to identify a redox neutral, theoretically high yielding route to a branched C6 alcohol. Enzymes capable of converting natural E. coli metabolites into 4-methyl-pentanol (4MP) via coenzyme A (CoA)-dependent chemistry were taken from nine different organisms to form a ten-step de novo pathway. Selectivity for 4MP is enhanced through the use of key enzymes acting on acyl-CoA intermediates, a carboxylic acid reductase from Nocardia iowensis and an alcohol dehydrogenase from Leifsonia sp. strain S749. One implementation of the full pathway from glucose demonstrates selective carbon chain extension and acid reduction with 4MP constituting 81% (90±7 mg l(-1)) of the observed alcohol products. The highest observed 4MP titre is 192±23 mg l(-1). These results demonstrate the ability of modular pathway screening to facilitate de novo pathway engineering.
Collapse
|
19
|
Promponas VJ, Ouzounis CA, Iliopoulos I. Experimental evidence validating the computational inference of functional associations from gene fusion events: a critical survey. Brief Bioinform 2012; 15:443-54. [PMID: 23220349 PMCID: PMC4017328 DOI: 10.1093/bib/bbs072] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
More than a decade ago, a number of methods were proposed for the inference of protein interactions, using whole-genome information from gene clusters, gene fusions and phylogenetic profiles. This structural and evolutionary view of entire genomes has provided a valuable approach for the functional characterization of proteins, especially those without sequence similarity to proteins of known function. Furthermore, this view has raised the real possibility to detect functional associations of genes and their corresponding proteins for any entire genome sequence. Yet, despite these exciting developments, there have been relatively few cases of real use of these methods outside the computational biology field, as reflected from citation analysis. These methods have the potential to be used in high-throughput experimental settings in functional genomics and proteomics to validate results with very high accuracy and good coverage. In this critical survey, we provide a comprehensive overview of 30 most prominent examples of single pairwise protein interaction cases in small-scale studies, where protein interactions have either been detected by gene fusion or yielded additional, corroborating evidence from biochemical observations. Our conclusion is that with the derivation of a validated gold-standard corpus and better data integration with big experiments, gene fusion detection can truly become a valuable tool for large-scale experimental biology.
Collapse
Affiliation(s)
- Vasilis J Promponas
- Institute of Agrobiotechnology, Centre for Research & Technology Hellas (CERTH), 57001 Thessaloniki, Greece.
| | | | | |
Collapse
|
20
|
Deme JC, Miousse IR, Plesa M, Kim JC, Hancock MA, Mah W, Rosenblatt DS, Coulton JW. Structural features of recombinant MMADHC isoforms and their interactions with MMACHC, proteins of mammalian vitamin B12 metabolism. Mol Genet Metab 2012; 107:352-62. [PMID: 22832074 DOI: 10.1016/j.ymgme.2012.07.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2012] [Accepted: 07/01/2012] [Indexed: 12/17/2022]
Abstract
The genes MMACHC and MMADHC encode critical proteins involved in the intracellular metabolism of cobalamin. Two clinical features, homocystinuria and methylmalonic aciduria, define inborn errors of these genes. Based on disease phenotypes, MMADHC acts at a branch point for cobalamin delivery, apparently exerting its function through interaction with MMACHC that demonstrates dealkylase and decyanase activities. Here we present biophysical analyses of MMADHC to identify structural features and to further characterize its interaction with MMACHC. Two recombinant tag-less isoforms of MMADHC (MMADHCΔ1-12 and MMADHCΔ1-61) were expressed and purified. Full length MMACHC and full length MMADHC were detected in whole cell lysates of human cells; by Western blotting, their molecular masses corresponded to purified recombinant proteins. By clear-native PAGE and by dynamic light scattering, recombinant MMADHCs were stable and monodisperse. Both species were monomeric, adopting extended conformations in solution. Circular dichroism and secondary structure predictions correlated with significant regions of disorder within the N-terminal domain of MMADHC. We found no evidence that MMADHC binds cobalamin. Phage panning against MMADHC predicted four binding regions on MMACHC, two of which overlap with predicted sites on MMACHC at which it may self-associate. Specific, concentration-dependent responses were observed for MMACHC binding to itself and to both MMADHC constructs. As estimated in the sub-micromolar range, the binding of MMACHC to itself was weaker compared to its interaction with either of the MMADHC isoforms. We propose that the function of MMADHC is exerted through its structured C-terminal domain via interactions with MMACHC.
Collapse
Affiliation(s)
- Justin C Deme
- Department of Microbiology and Immunology, McGill University, Montreal, Quebec, Canada
| | | | | | | | | | | | | | | |
Collapse
|
21
|
Takahashi-Iñiguez T, García-Hernandez E, Arreguín-Espinosa R, Flores ME. Role of vitamin B12 on methylmalonyl-CoA mutase activity. J Zhejiang Univ Sci B 2012; 13:423-37. [PMID: 22661206 DOI: 10.1631/jzus.b1100329] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Vitamin B(12) is an organometallic compound with important metabolic derivatives that act as cofactors of certain enzymes, which have been grouped into three subfamilies depending on their cofactors. Among them, methylmalonyl-CoA mutase (MCM) has been extensively studied. This enzyme catalyzes the reversible isomerization of L-methylmalonyl-CoA to succinyl-CoA using adenosylcobalamin (AdoCbl) as a cofactor participating in the generation of radicals that allow isomerization of the substrate. The crystal structure of MCM determined in Propionibacterium freudenreichii var. shermanii has helped to elucidate the role of this cofactor AdoCbl in the reaction to specify the mechanism by which radicals are generated from the coenzyme and to clarify the interactions between the enzyme, coenzyme, and substrate. The existence of human methylmalonic acidemia (MMA) due to the presence of mutations in MCM shows the importance of its role in metabolism. The recent crystallization of the human MCM has shown that despite being similar to the bacterial protein, there are significant differences in the structural organization of the two proteins. Recent studies have identified the involvement of an accessory protein called MMAA, which interacts with MCM to prevent MCM's inactivation or acts as a chaperone to promote regeneration of inactivated enzyme. The interdisciplinary studies using this protein as a model in different organisms have helped to elucidate the mechanism of action of this isomerase, the impact of mutations at a functional level and their repercussion in the development and progression of MMA in humans. It is still necessary to study the mechanisms involved in more detail using new methods.
Collapse
Affiliation(s)
- Tóshiko Takahashi-Iñiguez
- Department of Molecular Biology and Biotechnology, Institute of Biomedical Research, National Autonomous University of Mexico, D.F. 04510, Mexico.
| | | | | | | |
Collapse
|
22
|
Han Y, Hawkins AS, Adams MWW, Kelly RM. Epimerase (Msed_0639) and mutase (Msed_0638 and Msed_2055) convert (S)-methylmalonyl-coenzyme A (CoA) to succinyl-CoA in the Metallosphaera sedula 3-hydroxypropionate/4-hydroxybutyrate cycle. Appl Environ Microbiol 2012; 78:6194-202. [PMID: 22752162 PMCID: PMC3416614 DOI: 10.1128/aem.01312-12] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2012] [Accepted: 06/20/2012] [Indexed: 11/20/2022] Open
Abstract
Crenarchaeotal genomes encode the 3-hydroxypropionate/4-hydroxybutyrate (3-HP/4-HB) cycle for carbon dioxide fixation. Of the 13 enzymes putatively comprising the cycle, several of them, including methylmalonyl-coenzyme A (CoA) epimerase (MCE) and methylmalonyl-CoA mutase (MCM), which convert (S)-methylmalonyl-CoA to succinyl-CoA, have not been confirmed and characterized biochemically. In the genome of Metallosphaera sedula (optimal temperature [T(opt)], 73°C), the gene encoding MCE (Msed_0639) is adjacent to that encoding the catalytic subunit of MCM-α (Msed_0638), while the gene for the coenzyme B(12)-binding subunit of MCM (MCM-β) is located remotely (Msed_2055). The expression of all three genes was significantly upregulated under autotrophic compared to heterotrophic growth conditions, implying a role in CO(2) fixation. Recombinant forms of MCE and MCM were produced in Escherichia coli; soluble, active MCM was produced only if MCM-α and MCM-β were coexpressed. MCE is a homodimer and MCM is a heterotetramer (α(2)β(2)) with specific activities of 218 and 2.2 μmol/min/mg, respectively, at 75°C. The heterotetrameric MCM differs from the homo- or heterodimeric orthologs in other organisms. MCE was activated by divalent cations (Ni(2+), Co(2+), and Mg(2+)), and the predicted metal binding/active sites were identified through sequence alignments with less-thermophilic MCEs. The conserved coenzyme B(12)-binding motif (DXHXXG-SXL-GG) was identified in M. sedula MCM-β. The two enzymes together catalyzed the two-step conversion of (S)-methylmalonyl-CoA to succinyl-CoA, consistent with their proposed role in the 3-HP/4-HB cycle. Based on the highly conserved occurrence of single copies of MCE and MCM in Sulfolobaceae genomes, the M. sedula enzymes are likely to be representatives of these enzymes in the 3-HP/4-HB cycle in crenarchaeal thermoacidophiles.
Collapse
Affiliation(s)
- Yejun Han
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina, USA
| | - Aaron S. Hawkins
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina, USA
| | - Michael W. W. Adams
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia, USA
| | - Robert M. Kelly
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina, USA
| |
Collapse
|
23
|
Cracan V, Banerjee R. Novel B(12)-dependent acyl-CoA mutases and their biotechnological potential. Biochemistry 2012; 51:6039-46. [PMID: 22803641 DOI: 10.1021/bi300827v] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The recent spate of discoveries of novel acyl-CoA mutases has engendered a growing appreciation for the diversity of 5'-deoxyadenosylcobalamin-dependent rearrangement reactions. The prototype of the reaction catalyzed by these enzymes is the 1,2 interchange of a hydrogen atom with a thioester group leading to a change in the degree of carbon skeleton branching. These enzymes are predicted to share common architectural elements: a Rossman fold and a triose phosphate isomerase (TIM)-barrel domain for binding cofactor and substrate, respectively. Within this family, methylmalonyl-CoA mutase (MCM) is the best studied and is the only member found in organisms ranging from bacteria to man. MCM interconverts (2R)-methylmalonyl-CoA and succinyl-CoA. The more recently discovered family members include isobutyryl-CoA mutase (ICM), which interconverts isobutyryl-CoA and n-butyryl-CoA; ethylmalonyl-CoA mutase, which interconverts (2R)-ethylmalonyl-CoA and (2S)-methylsuccinyl-CoA; and 2-hydroxyisobutyryl-CoA mutase, which interconverts 2-hydroxyisobutyryl-CoA and (3S)-hydroxybutyryl-CoA. A variant in which the two subunits of ICM are fused to a G-protein chaperone, IcmF, has been described recently. In addition to its ICM activity, IcmF also catalyzes the interconversion of isovaleryl-CoA and pivalyl-CoA. This review focuses on the involvement of acyl-CoA mutases in central carbon and secondary bacterial metabolism and on their biotechnological potential for applications ranging from bioremediation to stereospecific synthesis of C2-C5 carboxylic acids and alcohols, and for production of potential commodity and specialty chemicals.
Collapse
Affiliation(s)
- Valentin Cracan
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, MI 48109-0600, USA
| | | |
Collapse
|
24
|
Yaneva N, Schuster J, Schäfer F, Lede V, Przybylski D, Paproth T, Harms H, Müller RH, Rohwerder T. Bacterial acyl-CoA mutase specifically catalyzes coenzyme B12-dependent isomerization of 2-hydroxyisobutyryl-CoA and (S)-3-hydroxybutyryl-CoA. J Biol Chem 2012; 287:15502-11. [PMID: 22433853 DOI: 10.1074/jbc.m111.314690] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Coenzyme B(12)-dependent acyl-CoA mutases are radical enzymes catalyzing reversible carbon skeleton rearrangements in carboxylic acids. Here, we describe 2-hydroxyisobutyryl-CoA mutase (HCM) found in the bacterium Aquincola tertiaricarbonis as a novel member of the mutase family. HCM specifically catalyzes the interconversion of 2-hydroxyisobutyryl- and (S)-3-hydroxybutyryl-CoA. Like isobutyryl-CoA mutase, HCM consists of a large substrate- and a small B(12)-binding subunit, HcmA and HcmB, respectively. However, it is thus far the only acyl-CoA mutase showing substrate specificity for hydroxylated carboxylic acids. Complete loss of 2-hydroxyisobutyric acid degradation capacity in hcmA and hcmB knock-out mutants established the central role of HCM in A. tertiaricarbonis for degrading substrates bearing a tert-butyl moiety, such as the fuel oxygenate methyl tert-butyl ether (MTBE) and its metabolites. Sequence analysis revealed several HCM-like enzymes in other bacterial strains not related to MTBE degradation, indicating that HCM may also be involved in other pathways. In all strains, hcmA and hcmB are associated with genes encoding for a putative acyl-CoA synthetase and a MeaB-like chaperone. Activity and substrate specificity of wild-type enzyme and active site mutants HcmA I90V, I90F, and I90Y clearly demonstrated that HCM belongs to a new subfamily of B(12)-dependent acyl-CoA mutases.
Collapse
Affiliation(s)
- Nadya Yaneva
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research (UFZ), 04318 Leipzig, Germany
| | | | | | | | | | | | | | | | | |
Collapse
|
25
|
Cracan V, Banerjee R. Novel coenzyme B12-dependent interconversion of isovaleryl-CoA and pivalyl-CoA. J Biol Chem 2011; 287:3723-32. [PMID: 22167181 DOI: 10.1074/jbc.m111.320051] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
5'-Deoxyadenosylcobalamin (AdoCbl)-dependent isomerases catalyze carbon skeleton rearrangements using radical chemistry. We have recently characterized a fusion protein that comprises the two subunits of the AdoCbl-dependent isobutyryl-CoA mutase flanking a G-protein chaperone and named it isobutyryl-CoA mutase fused (IcmF). IcmF catalyzes the interconversion of isobutyryl-CoA and n-butyryl-CoA, whereas GTPase activity is associated with its G-protein domain. In this study, we report a novel activity associated with IcmF, i.e. the interconversion of isovaleryl-CoA and pivalyl-CoA. Kinetic characterization of IcmF yielded the following values: a K(m) for isovaleryl-CoA of 62 ± 8 μM and V(max) of 0.021 ± 0.004 μmol min(-1) mg(-1) at 37 °C. Biochemical experiments show that an IcmF in which the base specificity loop motif NKXD is modified to NKXE catalyzes the hydrolysis of both GTP and ATP. IcmF is susceptible to rapid inactivation during turnover, and GTP conferred modest protection during utilization of isovaleryl-CoA as substrate. Interestingly, there was no protection from inactivation when either isobutyryl-CoA or n-butyryl-CoA was used as substrate. Detailed kinetic analysis indicated that inactivation is associated with loss of the 5'-deoxyadenosine moiety from the active site, precluding reformation of AdoCbl at the end of the turnover cycle. Under aerobic conditions, oxidation of the cob(II)alamin radical in the inactive enzyme results in accumulation of aquacobalamin. Because pivalic acid found in sludge can be used as a carbon source by some bacteria and isovaleryl-CoA is an intermediate in leucine catabolism, our discovery of a new isomerase activity associated with IcmF expands its metabolic potential.
Collapse
Affiliation(s)
- Valentin Cracan
- Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan 48109-0600, USA
| | | |
Collapse
|
26
|
Identification of missing genes and enzymes for autotrophic carbon fixation in crenarchaeota. J Bacteriol 2010; 193:1201-11. [PMID: 21169482 DOI: 10.1128/jb.01156-10] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Two autotrophic carbon fixation cycles have been identified in Crenarchaeota. The dicarboxylate/4-hydroxybutyrate cycle functions in anaerobic or microaerobic autotrophic members of the Thermoproteales and Desulfurococcales. The 3-hydroxypropionate/4-hydroxybutyrate cycle occurs in aerobic autotrophic Sulfolobales; a similar cycle may operate in autotrophic aerobic marine Crenarchaeota. Both cycles form succinyl-coenzyme A (CoA) from acetyl-CoA and two molecules of inorganic carbon, but they use different means. Both cycles have in common the (re)generation of acetyl-CoA from succinyl-CoA via identical intermediates. Here, we identified several missing enzymes/genes involved in the seven-step conversion of succinyl-CoA to two molecules of acetyl-CoA in Thermoproteus neutrophilus (Thermoproteales), Ignicoccus hospitalis (Desulfurococcales), and Metallosphaera sedula (Sulfolobales). The identified enzymes/genes include succinyl-CoA reductase, succinic semialdehyde reductase, 4-hydroxybutyrate-CoA ligase, bifunctional crotonyl-CoA hydratase/(S)-3-hydroxybutyryl-CoA dehydrogenase, and beta-ketothiolase. 4-Hydroxybutyryl-CoA dehydratase, which catalyzes a mechanistically intriguing elimination of water, is well conserved and rightly can be considered the key enzyme of these two cycles. In contrast, several of the other enzymes evolved from quite different sources, making functional predictions based solely on genome interpretation difficult, if not questionable.
Collapse
|