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Beauvieux A, Bourjea J, Fromentin JM, Jean C, Ciccione S, Ballorain K, Romero D, Dbouk Z, Hirschler A, Bertile F, Schull Q. Tracing troubles: Unveiling the hidden impact of inorganic contamination on juvenile green sea turtle. MARINE POLLUTION BULLETIN 2024; 208:117048. [PMID: 39368147 DOI: 10.1016/j.marpolbul.2024.117048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2024] [Revised: 09/09/2024] [Accepted: 09/23/2024] [Indexed: 10/07/2024]
Abstract
Human activities and climate change have negatively affected the world's oceans, leading to a decline of 30 to 60 % in coastal ecosystems' biodiversity and habitats. The projected increase in the human population to 9.7 billion by 2050 raises concerns about the sustainability of marine ecosystem conservation and exploitation. Marine turtles, as sentinel species, accumulate contaminants, including trace elements, due to their extensive migration and long-life span. However, there is a lack of data on the degree of contamination and their effects on marine turtles' health. This study focuses on assessing in-situ inorganic contamination in juvenile green sea turtles from La Réunion Island and its short-term impact on individual health, using conventional biomarkers and proteomics. The goals include examining contamination patterns in different tissues and identifying potential new biomarkers for long-term monitoring and conservation efforts. The study identified differential metal contamination between blood and scute samples, which could help illuminate temporal exposure to trace elements in turtle individuals. We also found that some conventional biomarkers were related to trace element exposure, while the proteome responded differently to various contaminant mixtures. Immune processes, cellular organization, and metabolism were impacted, indicating that contaminant mixtures in the wild would have an effect on turtle's health. Fifteen biomarker candidates associated with strong molecular responses of sea turtle to trace element contamination are proposed for future long-term monitoring. The findings emphasize the importance of using proteomic approaches to detect subtle physiological responses to contaminants in the wild and support the need for non-targeted analysis of trace elements in the biomonitoring of sea turtle health.
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Affiliation(s)
| | - Jérôme Bourjea
- MARBEC, Univ Montpellier, CNRS, Ifremer, IRD, Sète, France
| | | | - Claire Jean
- Centre d'Etude et de Découverte des Tortues Marines (CEDTM) Saint-Leu, Reunion Island, France
| | - Stéphane Ciccione
- Centre d'Etude et de Découverte des Tortues Marines (CEDTM) Saint-Leu, Reunion Island, France
| | - Katia Ballorain
- Kélonia, The Marine Turtle Observatory of Reunion Island, 46 rue du Gal de Gaulle, Saint-Leu, Reunion Island, France
| | - Diego Romero
- Toxicology Department, Faculty of Veterinary Medicine, University of Murcia, 30100 Murcia, Spain
| | - Zahraa Dbouk
- Université de Strasbourg, CNRS, IPHC UMR 7178, 23 rue du Loess, 67037, Strasbourg Cedex 2, France; Infrastructure Nationale de Protéomique ProFI, FR2048 CNRS CEA, Strasbourg 67087, France
| | - Aurélie Hirschler
- Université de Strasbourg, CNRS, IPHC UMR 7178, 23 rue du Loess, 67037, Strasbourg Cedex 2, France; Infrastructure Nationale de Protéomique ProFI, FR2048 CNRS CEA, Strasbourg 67087, France
| | - Fabrice Bertile
- Université de Strasbourg, CNRS, IPHC UMR 7178, 23 rue du Loess, 67037, Strasbourg Cedex 2, France; Infrastructure Nationale de Protéomique ProFI, FR2048 CNRS CEA, Strasbourg 67087, France
| | - Quentin Schull
- MARBEC, Univ Montpellier, CNRS, Ifremer, IRD, Sète, France
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2
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He S, Bai X, Xu Y. Structural insight into the role of thiolase from Fusobacterium nucleatum. Biochem Biophys Res Commun 2023; 688:149151. [PMID: 37951156 DOI: 10.1016/j.bbrc.2023.149151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Revised: 10/22/2023] [Accepted: 10/23/2023] [Indexed: 11/13/2023]
Abstract
Fusobacterium nucleatum (F. nucleatum) is an anaerobic gram-negative bacterium that was previously thought to be related to the progression of colorectal cancer. In F. nucleatum, thiolase participates in fatty acid metabolism, and it can catalyse the transfer of an acetyl group from acetyl-CoA to another molecule, typically a fatty acid or another molecule in the synthesis of lipids. To gain deeper insight into the molecular mechanism governing the function of thiolase in F. nucleatum (Fn0495), we herein report the structure of Fn0495. The monomer of Fn0495 consists of three subdomains, namely, the N-terminal domain (residues 1-117 and 252-270), the C-terminal domain (residues 273-393), and the loop domain (residues 118-251). Fn0495 shows a unique difference in the charge and structure of the substrate binding pocket compared with homologous proteins. This research found three conserved residues (Cys88, His357, and Cys387) in Fn0495 arranged near a potential substrate binding pocket. In this study, the conformational changes between the covering loop, catalytic cysteine loop, regulatory determinant region, and homologous protein were compared. These results will enhance our understanding of the molecular characteristics and roles of the thiolase family.
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Affiliation(s)
- Shanru He
- Department of Bioengineering, College of Life Science, Dalian Minzu University, Dalian, 116600, Liaoning, China; Key Laboratory of Biotechnology and Bioresources Utilization of Ministry of Education, College of Life Science, Dalian Minzu University, China
| | - Xue Bai
- Department of Bioengineering, College of Life Science, Dalian Minzu University, Dalian, 116600, Liaoning, China; Key Laboratory of Biotechnology and Bioresources Utilization of Ministry of Education, College of Life Science, Dalian Minzu University, China
| | - Yongbin Xu
- Department of Bioengineering, College of Life Science, Dalian Minzu University, Dalian, 116600, Liaoning, China; Key Laboratory of Biotechnology and Bioresources Utilization of Ministry of Education, College of Life Science, Dalian Minzu University, China; CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, Liaoning, China.
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3
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Singh R, Kundu P, Mishra VK, Singh BK, Bhattacharyya S, Das AK. Crystal structure of FadA2 thiolase from Mycobacterium tuberculosis and prediction of its substrate specificity and membrane-anchoring properties. FEBS J 2023; 290:3997-4022. [PMID: 37026388 DOI: 10.1111/febs.16792] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 03/17/2023] [Accepted: 04/05/2023] [Indexed: 04/08/2023]
Abstract
Tuberculosis (TB) is one of the leading causes of human death caused by Mycobacterium tuberculosis (Mtb). Mtb can enter into a long-lasting persistence where it can utilize fatty acids as the carbon source. Hence, fatty acid metabolism pathway enzymes are considered promising and pertinent mycobacterial drug targets. FadA2 (thiolase) is one of the enzymes involved in Mtb's fatty acid metabolism pathway. FadA2 deletion construct (ΔL136-S150) was designed to produce soluble protein. The crystal structure of FadA2 (ΔL136-S150) at 2.9 Å resolution was solved and analysed for membrane-anchoring region. The four catalytic residues of FadA2 are Cys99, His341, His390 and Cys427, and they belong to four loops with characteristic sequence motifs, i.e., CxT, HEAF, GHP and CxA. FadA2 is the only thiolase of Mtb which belongs to the CHH category containing the HEAF motif. Analysing the substrate-binding channel, it has been suggested that FadA2 is involved in the β-oxidation pathway, i.e., the degradative pathway, as the long-chain fatty acid can be accommodated in the channel. The catalysed reaction is favoured by the presence of two oxyanion holes, i.e., OAH1 and OAH2. OAH1 formation is unique in FadA2, formed by the NE2 of His390 present in the GHP motif and NE2 of His341 present in the HEAF motif, whereas OAH2 formation is similar to CNH category thiolase. Sequence and structural comparison with the human trifunctional enzyme (HsTFE-β) suggests the membrane-anchoring region in FadA2. Molecular dynamics simulations of FadA2 with a membrane containing POPE lipid were conducted to understand the role of a long insertion sequence of FadA2 in membrane anchoring.
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Affiliation(s)
- Rashika Singh
- Department of Biotechnology, Indian Institute of Technology Kharagpur, India
| | - Prasun Kundu
- Department of Biotechnology, Indian Institute of Technology Kharagpur, India
| | | | - Bina Kumari Singh
- School of Bioscience, Indian Institute of Technology Kharagpur, India
| | - Sudipta Bhattacharyya
- Department of Bioscience & Bioengineering, Indian Institute of Technology Jodhpur, India
| | - Amit Kumar Das
- Department of Biotechnology, Indian Institute of Technology Kharagpur, India
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4
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Allosteric Modulation of the Main Protease (MPro) of SARS-CoV-2 by Casticin—Insights from Molecular Dynamics Simulations. CHEMISTRY AFRICA 2022. [PMCID: PMC9261893 DOI: 10.1007/s42250-022-00411-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Inhibition of the main protease (Mpro) of SARS-CoV-2 has been suggested to be vital in shutting down viral replication in a host. Most efforts aimed at inhibiting MPro activity have been channeled into competitive inhibition at the active site, but this strategy will require a high inhibitor concentration and impressive inhibitor-MPro binding affinity. Allosteric inhibition can potentially serve as an effective strategy for alleviating these limitations. In this study, the ability of antiviral natural products to inhibit MPro in an allosteric fashion was explored with in silico techniques. Molecular docking revealed a strong interaction between casticin, an antiviral flavonoid, and Mpro at a site distant from the active site. This site, characterized as a distal site, has been shown to have an interdependent dynamic effect with the active site region. Mpro only, Mpro-peptide (binary) and Mpro-peptide-casticin (ternary) complexes were subjected to molecular dynamics simulations for 50 ns to investigate the modulatory activity of casticin binding on Mpro. Molecular dynamic simulations revealed that binding of casticin at the distal site interferes with the proper orientation of the peptide substrate in the oxyanion hole of the active site, and this could lead to a halt or decrease in catalytic activity. This study therefore highlights casticin as a potential allosteric modulator of the SARS-CoV-2 main protease, which could be optimized and developed into a potential lead compound for anti-SARS-CoV-2 chemotherapy.
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Helicobacter pylori FabX contains a [4Fe-4S] cluster essential for unsaturated fatty acid synthesis. Nat Commun 2021; 12:6932. [PMID: 34836944 PMCID: PMC8626469 DOI: 10.1038/s41467-021-27148-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Accepted: 10/29/2021] [Indexed: 11/08/2022] Open
Abstract
Unsaturated fatty acids (UFAs) are essential for functional membrane phospholipids in most bacteria. The bifunctional dehydrogenase/isomerase FabX is an essential UFA biosynthesis enzyme in the widespread human pathogen Helicobacter pylori, a bacterium etiologically related to 95% of gastric cancers. Here, we present the crystal structures of FabX alone and in complexes with an octanoyl-acyl carrier protein (ACP) substrate or with holo-ACP. FabX belongs to the nitronate monooxygenase (NMO) flavoprotein family but contains an atypical [4Fe-4S] cluster absent in all other family members characterized to date. FabX binds ACP via its positively charged α7 helix that interacts with the negatively charged α2 and α3 helices of ACP. We demonstrate that the [4Fe-4S] cluster potentiates FMN oxidation during dehydrogenase catalysis, generating superoxide from an oxygen molecule that is locked in an oxyanion hole between the FMN and the active site residue His182. Both the [4Fe-4S] and FMN cofactors are essential for UFA synthesis, and the superoxide is subsequently excreted by H. pylori as a major resource of peroxide which may contribute to its pathogenic function in the corrosion of gastric mucosa.
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6
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Engineering potassium activation into biosynthetic thiolase. Biochem J 2021; 478:3047-3062. [PMID: 34338286 DOI: 10.1042/bcj20210455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 07/26/2021] [Accepted: 07/30/2021] [Indexed: 11/17/2022]
Abstract
Activation of enzymes by monovalent cations (M+) is a widespread phenomenon in biology. Despite this, there are few structure-based studies describing the underlying molecular details. Thiolases are a ubiquitous and highly conserved family of enzymes containing both K+-activated and K+-independent members. Guided by structures of naturally occurring K+-activated thiolases, we have used a structure-based approach to engineer K+-activation into a K+-independent thiolase. To our knowledge, this is the first demonstration of engineering K+-activation into an enzyme, showing the malleability of proteins to accommodate M+ ions as allosteric regulators. We show that a few protein structural features encode K+-activation in this class of enzyme. Specifically, two residues near the substrate-binding site are sufficient for K+-activation: A tyrosine residue is required to complete the K+ coordination sphere, and a glutamate residue provides a compensating charge for the bound K+ ion. Further to these, a distal residue is important for positioning a K+-coordinating water molecule that forms a direct hydrogen bond to the substrate. The stability of a cation-π interaction between a positively charged residue and the substrate is determined by the conformation of the loop surrounding the substrate-binding site. Our results suggest that this cation-π interaction effectively overrides K+-activation, and is, therefore, destabilised in K+-activated thiolases. Evolutionary conservation of these amino acids provides a promising signature sequence for predicting K+-activation in thiolases. Together, our structural, biochemical and bioinformatic work provide important mechanistic insights into how enzymes can be allosterically activated by M+ ions.
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Dalwani S, Lampela O, Leprovost P, Schmitz W, Juffer A, Wierenga RK, Venkatesan R. Substrate specificity and conformational flexibility properties of the Mycobacterium tuberculosis β-oxidation trifunctional enzyme. J Struct Biol 2021; 213:107776. [PMID: 34371166 DOI: 10.1016/j.jsb.2021.107776] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 06/30/2021] [Accepted: 08/04/2021] [Indexed: 10/20/2022]
Abstract
The Mycobacterium tuberculosis trifunctional enzyme (MtTFE) is an α2β2 tetrameric enzyme. The α -chain harbors the 2E-enoyl-CoA hydratase (ECH) and 3S-hydroxyacyl-CoA dehydrogenase (HAD) activities and the β -chain provides the 3-ketoacyl-CoA thiolase (KAT) activity. Enzyme kinetic data reported here show that medium and long chain enoyl-CoA molecules are preferred substrates for MtTFE. Modelling studies indicate how the linear medium and long chain acyl chains of these substrates can bind to each of the active sites. In addition, crystallographic binding studies have identified three new CoA binding sites which are different from the previously known CoA binding sites of the three TFE active sites. Structure comparisons provide new insights into the properties of ECH, HAD and KAT active sites of MtTFE. The interactions of the adenine moiety of CoA with loop-2 of the ECH active site cause a conformational change of this loop by which a competent ECH active site is formed. The NAD+ binding domain (domain C) of the HAD part of MtTFE has only a few interactions with the rest of the complex and adopts a range of open conformations, whereas the A-domain of the ECH part is rigidly fixed with respect to the HAD part. Two loops, the CB1-CA1 region and the catalytic CB4-CB5 loop, near the thiolase active site and the thiolase dimer interface, have high B-factors. Structure comparisons suggest that a competent and stable thiolase dimer is formed only when complexed with the α -chains, highlighting the importance of the assembly for the proper functioning of the complex.
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Affiliation(s)
- Subhadra Dalwani
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
| | - Outi Lampela
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland; Biocenter Oulu, University of Oulu, Oulu, Finland
| | - Pierre Leprovost
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland; Biocenter Oulu, University of Oulu, Oulu, Finland
| | - Werner Schmitz
- Theoder-Boveri-Institut für Biowissenschaften der Universität Würzburg, Würzburg, Germany
| | - Andre Juffer
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland; Biocenter Oulu, University of Oulu, Oulu, Finland
| | - Rik K Wierenga
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland; Biocenter Oulu, University of Oulu, Oulu, Finland
| | - Rajaram Venkatesan
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland.
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8
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Cao TP, Yi H, Dhanasingh I, Ghosh S, Choi JM, Lee KH, Ryu S, Kim HS, Lee SH. Non-catalytic-Region Mutations Conferring Transition of Class A β-Lactamases Into ESBLs. Front Mol Biosci 2020; 7:598998. [PMID: 33335913 PMCID: PMC7737660 DOI: 10.3389/fmolb.2020.598998] [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: 08/26/2020] [Accepted: 10/28/2020] [Indexed: 12/03/2022] Open
Abstract
Despite class A ESBLs carrying substitutions outside catalytic regions, such as Cys69Tyr or Asn136Asp, have emerged as new clinical threats, the molecular mechanisms underlying their acquired antibiotics-hydrolytic activity remains unclear. We discovered that this non-catalytic-region (NCR) mutations induce significant dislocation of β3-β4 strands, conformational changes in critical residues associated with ligand binding to the lid domain, dynamic fluctuation of Ω-loop and β3-β4 elements. Such structural changes increase catalytic regions’ flexibility, enlarge active site, and thereby accommodate third-generation cephalosporin antibiotics, ceftazidime (CAZ). Notably, the electrostatic property around the oxyanion hole of Cys69Tyr ESBL is significantly changed, resulting in possible additional stabilization of the acyl-enzyme intermediate. Interestingly, the NCR mutations are as effective for antibiotic resistance by altering the structure and dynamics in regions mediating substrate recognition and binding as single amino-acid substitutions in the catalytic region of the canonical ESBLs. We believe that our findings are crucial in developing successful therapeutic strategies against diverse class A ESBLs, including the new NCR-ESBLs.
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Affiliation(s)
- Thinh-Phat Cao
- Department of Cellular and Molecular Medicine, Chosun University School of Medicine, Gwangju, South Korea.,Department of Biomedical Sciences, Gwangju Alzheimer's Disease and Related Dementia Cohort Research Center, College of Natural Sciences and Public Health and Safety, Chosun University, Gwangju, South Korea
| | - Hyojeong Yi
- Division of Biosystems & Biomedical Sciences, College of Health Sciences, Korea University, Seoul, South Korea
| | - Immanuel Dhanasingh
- Department of Cellular and Molecular Medicine, Chosun University School of Medicine, Gwangju, South Korea
| | - Suparna Ghosh
- Department of Cellular and Molecular Medicine, Chosun University School of Medicine, Gwangju, South Korea
| | - Jin Myung Choi
- Department of Cellular and Molecular Medicine, Chosun University School of Medicine, Gwangju, South Korea
| | - Kun Ho Lee
- Department of Biomedical Sciences, Gwangju Alzheimer's Disease and Related Dementia Cohort Research Center, College of Natural Sciences and Public Health and Safety, Chosun University, Gwangju, South Korea.,Aging Neuroscience Research Group, Korea Brain Research Institute, Daegu, South Korea
| | - Seol Ryu
- Department of Chemistry, Chosun University, Gwangju, South Korea
| | - Heenam Stanley Kim
- Division of Biosystems & Biomedical Sciences, College of Health Sciences, Korea University, Seoul, South Korea
| | - Sung Haeng Lee
- Department of Cellular and Molecular Medicine, Chosun University School of Medicine, Gwangju, South Korea.,Department of Biomedical Sciences, Gwangju Alzheimer's Disease and Related Dementia Cohort Research Center, College of Natural Sciences and Public Health and Safety, Chosun University, Gwangju, South Korea
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9
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Hong J, Park W, Seo H, Kim IK, Kim KJ. Crystal structure of an acetyl-CoA acetyltransferase from PHB producing bacterium Bacillus cereus ATCC 14579. Biochem Biophys Res Commun 2020; 533:442-448. [PMID: 32972748 DOI: 10.1016/j.bbrc.2020.09.048] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2020] [Accepted: 09/14/2020] [Indexed: 10/24/2022]
Abstract
Bacillus cereus ATCC 14579 is a known polyhydroxybutyrate (PHB)-producing microorganism that possesses genes associated with PHB synthesis such as PhaA, PhaB, and PHA synthases. PhaA (i.e., thiolase) is the first enzyme in the PHA biosynthetic pathway, which catalyze the condensation of two acetyl-CoA molecules to acetoacetyl-CoA. Our study elucidated the crystal structure of PhaA in Bacillus cereus ATCC 14579 (BcTHL) in its apo- and CoA-bound forms. BcTHL adopts a type II biosynthetic thiolase structure by forming a tetramer. The crystal structure of CoA-complexed BcTHL revealed that the substrate binding site of BcTHL is constituted by different residues compared with other known thiolases. Our study also revealed that Arg221, a residue involved in ADP binding, undergoes a positional conformational change upon the binding of the CoA molecule.
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Affiliation(s)
- Jiyeon Hong
- School of Life Sciences, KNU Creative BioResearch Group, Kyungpook National University, Daegu, 41566, Republic of Korea; KNU Institute for Microorganisms, Kyungpook National University, Daegu, 41566, Republic of Korea
| | - Woojin Park
- School of Life Sciences, KNU Creative BioResearch Group, Kyungpook National University, Daegu, 41566, Republic of Korea; KNU Institute for Microorganisms, Kyungpook National University, Daegu, 41566, Republic of Korea
| | - Hogyun Seo
- School of Life Sciences, KNU Creative BioResearch Group, Kyungpook National University, Daegu, 41566, Republic of Korea; KNU Institute for Microorganisms, Kyungpook National University, Daegu, 41566, Republic of Korea
| | - Il-Kwon Kim
- KNU Institute for Microorganisms, Kyungpook National University, Daegu, 41566, Republic of Korea
| | - Kyung-Jin Kim
- School of Life Sciences, KNU Creative BioResearch Group, Kyungpook National University, Daegu, 41566, Republic of Korea; KNU Institute for Microorganisms, Kyungpook National University, Daegu, 41566, Republic of Korea.
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10
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Poater A. Michael Acceptors Tuned by the Pivotal Aromaticity of Histidine to Block COVID-19 Activity. J Phys Chem Lett 2020; 11:6262-6265. [PMID: 32658489 PMCID: PMC7376971 DOI: 10.1021/acs.jpclett.0c01828] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Accepted: 07/13/2020] [Indexed: 05/20/2023]
Abstract
The question of whether COVID protease (SARS-CoV-2 Mpro) can be blocked by inhibitors has been examined, with a particularly successful performance exhibited by α-ketoamide derivative substrates like 13b of Hilgenfeld and co-workers (Zhang, L., et al. Science 2020, 368, 409-412). After the biological characterization, here density functional theory calculations explain not only how inhibitor 13b produces a thermodynamically favorable interaction but also how to reach it kinetically. The controversial and unprovable concept of aromaticity here enjoys being the agent that rationalizes the seemingly innocent role of histidine (His41 of Mpro). It has a hydrogen bond with the hydroxyl group and is the proton carrier of the thiol of Cys145 at almost zero energy cost that favors the interaction with the inhibitor that acts as a Michael acceptor.
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Affiliation(s)
- Albert Poater
- Institut de Química Computacional i Catàlisi
and Departament de Química, Universitat de
Girona, C/Ma Aurèlia Capmany 69, 17003
Girona, Catalonia, Spain
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11
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Structural basis for differentiation between two classes of thiolase: Degradative vs biosynthetic thiolase. JOURNAL OF STRUCTURAL BIOLOGY-X 2020; 4:100018. [PMID: 32647822 PMCID: PMC7337054 DOI: 10.1016/j.yjsbx.2019.100018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 12/17/2019] [Accepted: 12/27/2019] [Indexed: 11/23/2022]
Abstract
Thiolases are a well characterized family of enzymes with two distinct categories: degradative, β-ketoadipyl-CoA thiolases and biosynthetic, acetoacetyl-CoA thiolases. Both classes share an identical catalytic triad but catalyze reactions in opposite directions. Moreover, it is established that in contrast to the biosynthetic thiolases the degradative thiolases can accept substrates with broad chain lengths. Hitherto, no residue or structural pattern has been recognized that might help to discern the two thiolases, here we exploit, a tetrameric degradative thiolase from Pseudomonas putida KT2440 annotated as PcaF, as a model system to understand features which distinguishes the two classes using structural studies and bioinformatics analyses. Degradative thiolases have different active site architecture when compared to biosynthetic thiolases, demonstrating the dissimilar chemical nature of the active site architecture. Both thiolases deploy different "anchoring residues" to tether the large Coenzyme A (CoA) or CoA derivatives. Interestingly, the H356 of the catalytic triad in PcaF is directly involved in tethering the CoA/CoA derivatives into the active site and we were able to trap a gridlocked thiolase structure of the H356A mutant, where the CoA was found to be covalently linked to the catalytic cysteine residue, inhibiting the overall reaction. Further, X-ray structures with two long chain CoA derivatives, hexanal-CoA and octanal-CoA helped in delineating the long tunnel of 235 Å2 surface area in PcaF and led to identification of a unique covering loop exclusive to degradative thiolases that plays an active role in determining the tunnel length and the nature of the binding substrate.
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Key Words
- A-mutant-HAL-CoA, A-mutant-hexanal CoA complex
- A-mutant-Hex-CoA, A-mutant-Hexanoyl CoA complex
- A-mutants, H356A Mutant
- AA-mutants, H356A-C386A Mutant
- AS-mutant-OAL-CoA, AS-mutant-octanal CoA complex
- AS-mutant-Oct-CoA, AS-mutant-Octanoyl CoA complex
- AS-mutants, H356A-C90S Mutant
- Covalent locking
- Covering loop
- HAL, hexanal
- Hex-CoA, Hexanoyl CoA
- Hexanoyl CoA
- Mtb-thiolase, Mycobacterium tuberculosis thiolase
- OAL, octanal
- Oct-CoA, Octanoyl CoA
- Octanoyl CoA
- PcaF, β-ketoadipyl-CoA thiolase
- Tunnel
- Zr-thiolase, Zoogleria ramigera thiolase
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12
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Yuan T, Yang M, Gehring K, Sampson NS. Mycobacterium tuberculosis Exploits a Heterohexameric Enoyl-CoA Hydratase Retro-Aldolase Complex for Cholesterol Catabolism. Biochemistry 2019; 58:4224-4235. [PMID: 31568719 DOI: 10.1021/acs.biochem.9b00673] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Cholesterol catabolism plays an important role in Mycobacterium tuberculosis's (Mtb's) survival and persistence in the host. Mtb exploits three β-oxidation cycles to fully degrade the side chain of cholesterol. Five cistronic genes in a single operon encode three enzymes, 3-oxo-4-pregnene-20-carboxyl-CoA dehydrogenase (ChsE1-ChsE2), 3-oxo-4,17-pregnadiene-20-carboxyl-CoA hydratase (ChsH1-ChsH2), and 17-hydroxy-3-oxo-4-pregnene-20-carboxyl-CoA retro-aldolase (Ltp2), to perform the last β-oxidation cycle in this pathway. Among these three enzymes, ChsH1-ChsH2 and Ltp2 form a protein complex that is required for the catalysis of carbon-carbon bond cleavage. In this work, we report the structure of the full length ChsH1-ChsH2-Ltp2 complex based on small-angle X-ray scattering and single-particle electron microscopy data. Mutagenesis experiments confirm the requirement for Ltp2 to catalyze the retro-aldol reaction. The structure illustrates how acyl transfer between enzymes may occur. Each protomer of the ChsH1-ChsH2-Ltp2 complex contains three protein components: a chain of ChsH1, a chain of ChsH2, and a chain of Ltp2. Two protomers dimerize at the interface of Ltp2 to form a heterohexameric structure. This unique heterohexameric structure of the ChsH1-ChsH2-Ltp2 complex provides entry to further understand the mechanism of cholesterol catabolism in Mtb.
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Affiliation(s)
- Tianao Yuan
- Department of Chemistry , Stony Brook University , Stony Brook , New York 11794-3400 , United States
| | - Meng Yang
- Department of Biochemistry , McGill University , Montreal , Quebec H3A 0G4 , Canada
| | - Kalle Gehring
- Department of Biochemistry , McGill University , Montreal , Quebec H3A 0G4 , Canada
| | - Nicole S Sampson
- Department of Chemistry , Stony Brook University , Stony Brook , New York 11794-3400 , United States
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13
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Abstract
Excessive intake of high-energy diets is an important cause of most obesity. The intervention of rats with high-fat diet can replicate the ideal animal model for studying the occurrence of human nutritional obesity. Proteomics and bioinformatics analyses can help us to systematically and comprehensively study the effect of high-fat diet on rat liver. In the present study, 4056 proteins were identified in rat liver by using tandem mass tag. A total of 198 proteins were significantly changed, of which 103 were significantly up-regulated and ninety-five were significantly down-regulated. These significant differentially expressed proteins are primarily involved in lipid metabolism and glucose metabolism processes. The intake of a high-fat diet forces the body to maintain physiological balance by regulating these key protein spots to inhibit fatty acid synthesis, promote fatty acid oxidation and accelerate fatty acid degradation. The present study enriches our understanding of metabolic disorders induced by high-fat diets at the protein level.
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14
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The peroxisomal zebrafish SCP2-thiolase (type-1) is a weak transient dimer as revealed by crystal structures and native mass spectrometry. Biochem J 2019; 476:307-332. [PMID: 30573650 DOI: 10.1042/bcj20180788] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Revised: 12/12/2018] [Accepted: 12/20/2018] [Indexed: 12/19/2022]
Abstract
The SCP2 (sterol carrier protein 2)-thiolase (type-1) functions in the vertebrate peroxisomal, bile acid synthesis pathway, converting 24-keto-THC-CoA and CoA into choloyl-CoA and propionyl-CoA. This conversion concerns the β-oxidation chain shortening of the steroid fatty acyl-moiety of 24-keto-THC-CoA. This class of dimeric thiolases has previously been poorly characterized. High-resolution crystal structures of the zebrafish SCP2-thiolase (type-1) now reveal an open catalytic site, shaped by residues of both subunits. The structure of its non-dimerized monomeric form has also been captured in the obtained crystals. Four loops at the dimer interface adopt very different conformations in the monomeric form. These loops also shape the active site and their structural changes explain why a competent active site is not present in the monomeric form. Native mass spectrometry studies confirm that the zebrafish SCP2-thiolase (type-1) as well as its human homolog are weak transient dimers in solution. The crystallographic binding studies reveal the mode of binding of CoA and octanoyl-CoA in the active site, highlighting the conserved geometry of the nucleophilic cysteine, the catalytic acid/base cysteine and the two oxyanion holes. The dimer interface of SCP2-thiolase (type-1) is equally extensive as in other thiolase dimers; however, it is more polar than any of the corresponding interfaces, which correlates with the notion that the enzyme forms a weak transient dimer. The structure comparison of the monomeric and dimeric forms suggests functional relevance of this property. These comparisons provide also insights into the structural rearrangements that occur when the folded inactive monomers assemble into the mature dimer.
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15
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Bonk BM, Tarasova Y, Hicks MA, Tidor B, Prather KL. Rational design of thiolase substrate specificity for metabolic engineering applications. Biotechnol Bioeng 2018; 115:2167-2182. [PMID: 29877597 PMCID: PMC6131064 DOI: 10.1002/bit.26737] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2018] [Revised: 05/14/2018] [Accepted: 05/31/2018] [Indexed: 12/29/2022]
Abstract
Metabolic engineering efforts require enzymes that are both highly active and specific toward the synthesis of a desired output product to be commercially feasible. The 3-hydroxyacid (3HA) pathway, also known as the reverse β-oxidation or coenzyme-A-dependent chain-elongation pathway, can allow for the synthesis of dozens of useful compounds of various chain lengths and functionalities. However, this pathway suffers from byproduct formation, which lowers the yields of the desired longer chain products, as well as increases downstream separation costs. The thiolase enzyme catalyzes the first reaction in this pathway, and its substrate specificity at each of its two catalytic steps sets the chain length and composition of the chemical scaffold upon which the other downstream enzymes act. However, there have been few attempts reported in the literature to rationally engineer thiolase substrate specificity. In this study, we present a model-guided, rational design study of ordered substrate binding applied to two biosynthetic thiolases, with the goal of increasing the ratio of C6/C4 products formed by the 3HA pathway, 3-hydroxy-hexanoic acid and 3-hydroxybutyric acid. We identify thiolase mutants that result in nearly 10-fold increases in C6/C4 selectivity. Our findings can extend to other pathways that employ the thiolase for chain elongation, as well as expand our knowledge of sequence-structure-function relationship for this important class of enzymes.
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Affiliation(s)
- Brian M. Bonk
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA
- Computer Science and Artificial Intelligence Laboratory (CSAIL), Massachusetts Institute of Technology, Cambridge, MA
| | - Yekaterina Tarasova
- Microbiology Graduate Program, Massachusetts Institute of Technology, Cambridge, MA
| | - Michael A. Hicks
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA
| | - Bruce Tidor
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA
- Computer Science and Artificial Intelligence Laboratory (CSAIL), Massachusetts Institute of Technology, Cambridge, MA
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA
| | - Kristala L.J. Prather
- Microbiology Graduate Program, Massachusetts Institute of Technology, Cambridge, MA
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA
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16
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Sagong HY, Son HF, Choi SY, Lee SY, Kim KJ. Structural Insights into Polyhydroxyalkanoates Biosynthesis. Trends Biochem Sci 2018; 43:790-805. [PMID: 30139647 DOI: 10.1016/j.tibs.2018.08.005] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Revised: 07/27/2018] [Accepted: 08/04/2018] [Indexed: 12/25/2022]
Abstract
Polyhydroxyalkanoates (PHAs) are diverse biopolyesters produced by numerous microorganisms and have attracted much attention as a substitute for petroleum-based polymers. Despite several decades of study, the detailed molecular mechanisms of PHA biosynthesis have remained unknown due to the lack of structural information on the key PHA biosynthetic enzyme PHA synthase. The recently determined crystal structure of PHA synthase, together with the structures of acetyl-coenzyme A (CoA) acetyltransferase and reductase, have changed this situation. Structural and biochemical studies provided important clues for the molecular mechanisms of each enzyme as well as the overall mechanism of PHA biosynthesis from acetyl-CoA. This new information and knowledge is expected to facilitate production of designed novel PHAs and also enhanced production of PHAs.
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Affiliation(s)
- Hye-Young Sagong
- School of Life Sciences, KNU Creative BioResearch Group, Kyungpook National University, Daegu 41566, Republic of Korea; KNU Institute for Microorganisms, Kyungpook National University, Daegu 41566, Republic of Korea
| | - Hyeoncheol Francis Son
- School of Life Sciences, KNU Creative BioResearch Group, Kyungpook National University, Daegu 41566, Republic of Korea; KNU Institute for Microorganisms, Kyungpook National University, Daegu 41566, Republic of Korea
| | - So Young Choi
- Metabolic and Biomolecular Engineering National Research Laboratory, Department of Chemical and Biomolecular Engineering (BK21 Plus Program), BioProcess Engineering Research Center, Center for Systems and Synthetic Biotechnology, and Institute for the BioCentury, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Sang Yup Lee
- Metabolic and Biomolecular Engineering National Research Laboratory, Department of Chemical and Biomolecular Engineering (BK21 Plus Program), BioProcess Engineering Research Center, Center for Systems and Synthetic Biotechnology, and Institute for the BioCentury, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea.
| | - Kyung-Jin Kim
- School of Life Sciences, KNU Creative BioResearch Group, Kyungpook National University, Daegu 41566, Republic of Korea; KNU Institute for Microorganisms, Kyungpook National University, Daegu 41566, Republic of Korea.
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17
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Torres-Salas P, Bernal V, López-Gallego F, Martínez-Crespo J, Sánchez-Murcia PA, Barrera V, Morales-Jiménez R, García-Sánchez A, Mañas-Fernández A, Seoane JM, Sagrera Polo M, Miranda JD, Calvo J, Huertas S, Torres JL, Alcalde-Bascones A, González-Barrera S, Gago F, Morreale A, González-Barroso MDM. Engineering Erg10 Thiolase from Saccharomyces cerevisiae as a Synthetic Toolkit for the Production of Branched-Chain Alcohols. Biochemistry 2018; 57:1338-1348. [PMID: 29360348 DOI: 10.1021/acs.biochem.7b01186] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Thiolases catalyze the condensation of acyl-CoA thioesters through the Claisen condensation reaction. The best described enzymes usually yield linear condensation products. Using a combined computational/experimental approach, and guided by structural information, we have studied the potential of thiolases to synthesize branched compounds. We have identified a bulky residue located at the active site that blocks proper accommodation of substrates longer than acetyl-CoA. Amino acid replacements at such a position exert effects on the activity and product selectivity of the enzymes that are highly dependent on a protein scaffold. Among the set of five thiolases studied, Erg10 thiolase from Saccharomyces cerevisiae showed no acetyl-CoA/butyryl-CoA branched condensation activity, but variants at position F293 resulted the most active and selective biocatalysts for this reaction. This is the first time that a thiolase has been engineered to synthesize branched compounds. These novel enzymes enrich the toolbox of combinatorial (bio)chemistry, paving the way for manufacturing a variety of α-substituted synthons. As a proof of concept, we have engineered Clostridium's 1-butanol pathway to obtain 2-ethyl-1-butanol, an alcohol that is interesting as a branched model compound.
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Affiliation(s)
- Pamela Torres-Salas
- Centro de Tecnología de Repsol, REPSOL S. A. Calle Agustín de Betancourt , s/n, 28935 Móstoles, Madrid, Spain
| | - Vicente Bernal
- Centro de Tecnología de Repsol, REPSOL S. A. Calle Agustín de Betancourt , s/n, 28935 Móstoles, Madrid, Spain
| | - Fernando López-Gallego
- Centro de Tecnología de Repsol, REPSOL S. A. Calle Agustín de Betancourt , s/n, 28935 Móstoles, Madrid, Spain.,CIC biomaGUNE , Paseo de Miramón 182, 20014 San Sebastián, Spain.,ARAID Foundation , Zaragoza, Spain
| | - Javier Martínez-Crespo
- Centro de Tecnología de Repsol, REPSOL S. A. Calle Agustín de Betancourt , s/n, 28935 Móstoles, Madrid, Spain
| | - Pedro A Sánchez-Murcia
- Departamento de Ciencias Biomédicas and "Unidad Asociada IQM-CSIC", Universidad de Alcalá , E-28805 Alcalá de Henares, Madrid, Spain
| | - Victor Barrera
- Centro de Tecnología de Repsol, REPSOL S. A. Calle Agustín de Betancourt , s/n, 28935 Móstoles, Madrid, Spain
| | - Rocío Morales-Jiménez
- Centro de Tecnología de Repsol, REPSOL S. A. Calle Agustín de Betancourt , s/n, 28935 Móstoles, Madrid, Spain
| | - Ana García-Sánchez
- Centro de Tecnología de Repsol, REPSOL S. A. Calle Agustín de Betancourt , s/n, 28935 Móstoles, Madrid, Spain
| | - Aurora Mañas-Fernández
- Centro de Tecnología de Repsol, REPSOL S. A. Calle Agustín de Betancourt , s/n, 28935 Móstoles, Madrid, Spain
| | - José M Seoane
- Centro de Tecnología de Repsol, REPSOL S. A. Calle Agustín de Betancourt , s/n, 28935 Móstoles, Madrid, Spain
| | - Marta Sagrera Polo
- Centro de Investigaciones Biológicas (CSIC) , Calle Ramiro de Maeztu 9, 28040 Madrid, Spain
| | - Juande D Miranda
- Centro de Tecnología de Repsol, REPSOL S. A. Calle Agustín de Betancourt , s/n, 28935 Móstoles, Madrid, Spain
| | - Javier Calvo
- CIC biomaGUNE , Paseo de Miramón 182, 20014 San Sebastián, Spain
| | - Sonia Huertas
- Centro de Tecnología de Repsol, REPSOL S. A. Calle Agustín de Betancourt , s/n, 28935 Móstoles, Madrid, Spain
| | - José L Torres
- Centro de Tecnología de Repsol, REPSOL S. A. Calle Agustín de Betancourt , s/n, 28935 Móstoles, Madrid, Spain
| | - Ana Alcalde-Bascones
- Centro de Tecnología de Repsol, REPSOL S. A. Calle Agustín de Betancourt , s/n, 28935 Móstoles, Madrid, Spain
| | - Sergio González-Barrera
- Centro de Tecnología de Repsol, REPSOL S. A. Calle Agustín de Betancourt , s/n, 28935 Móstoles, Madrid, Spain
| | - Federico Gago
- Departamento de Ciencias Biomédicas and "Unidad Asociada IQM-CSIC", Universidad de Alcalá , E-28805 Alcalá de Henares, Madrid, Spain
| | - Antonio Morreale
- Centro de Tecnología de Repsol, REPSOL S. A. Calle Agustín de Betancourt , s/n, 28935 Móstoles, Madrid, Spain
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18
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Marshall AC, Bond CS, Bruning JB. Structure of Aspergillus fumigatus Cytosolic Thiolase: Trapped Tetrahedral Reaction Intermediates and Activation by Monovalent Cations. ACS Catal 2018. [DOI: 10.1021/acscatal.7b02873] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Andrew C. Marshall
- Institute
for Photonics and Advanced Sensing (IPAS), School of Biological Sciences, The University of Adelaide, Adelaide, South Australia 5005, Australia
| | - Charles S. Bond
- School
of Molecular Sciences, The University of Western Australia, Crawley, Western Australia 6009, Australia
| | - John B. Bruning
- Institute
for Photonics and Advanced Sensing (IPAS), School of Biological Sciences, The University of Adelaide, Adelaide, South Australia 5005, Australia
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19
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Blaisse MR, Fu B, Chang MCY. Structural and Biochemical Studies of Substrate Selectivity in Ascaris suum Thiolases. Biochemistry 2018; 57:3155-3166. [PMID: 29381332 DOI: 10.1021/acs.biochem.7b01123] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Thiolases are a class of carbon-carbon bond forming enzymes with important applications in biotechnology and metabolic engineering as they provide a general method for the condensation of two acyl coenzyme A (CoA) substrates. As such, developing a greater understanding of their substrate selectivity would expand our ability to engineer the enzymatic or microbial production of a broad range of small-molecule targets. Here, we report the crystal structures and biochemical characterization of Acat2 and Acat5, two biosynthetic thiolases from Ascaris suum with varying selectivity toward branched compared to linear compounds. The structure of the Acat2-C91S mutant bound to propionyl-CoA shows that the terminal methyl group of the substrate, representing the α-branch point, is directed toward the conserved Phe 288 and Met 158 residues. In Acat5, the Phe ring is rotated to accommodate a hydroxyl-π interaction with an adjacent Thr side chain, decreasing space in the binding pocket and possibly accounting for its strong preference for linear substrates compared to Acat2. Comparison of the different Acat thiolase structures shows that Met 158 is flexible, adopting alternate conformations with the side chain rotated toward or away from a covering loop at the back of the active site. Mutagenesis of residues in the covering loop in Acat5 with the corresponding residues from Acat2 allows for highly increased accommodation of branched substrates, whereas the converse mutations do not significantly affect Acat2 substrate selectivity. Our results suggest an important contribution of second-shell residues to thiolase substrate selectivity and offer insights into engineering this enzyme class.
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20
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Harijan RK, Kiema TR, Syed SM, Qadir I, Mazet M, Bringaud F, Michels PAM, Wierenga RK. Crystallographic substrate binding studies of Leishmania mexicana SCP2-thiolase (type-2): unique features of oxyanion hole-1. Protein Eng Des Sel 2017; 30:225-233. [PMID: 28062645 DOI: 10.1093/protein/gzw080] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Accepted: 12/15/2016] [Indexed: 12/26/2022] Open
Abstract
C Structures of the C123A variant of the dimeric Leishmania mexicana SCP2-thiolase (type-2) (Lm-thiolase), complexed with acetyl-CoA and acetoacetyl-CoA, respectively, are reported. The catalytic site of thiolase contains two oxyanion holes, OAH1 and OAH2, which are important for catalysis. The two structures reveal for the first time the hydrogen bond interactions of the CoA-thioester oxygen atom of the substrate with the hydrogen bond donors of OAH1 of a CHH-thiolase. The amino acid sequence fingerprints ( xS, EAF, G P) of three catalytic loops identify the active site geometry of the well-studied CNH-thiolases, whereas SCP2-thiolases (type-1, type-2) are classified as CHH-thiolases, having as corresponding fingerprints xS, DCF and G P. In all thiolases, OAH2 is formed by the main chain NH groups of two catalytic loops. In the well-studied CNH-thiolases, OAH1 is formed by a water (of the Wat-Asn(NEAF) dyad) and NE2 (of the GHP-histidine). In the two described liganded Lm-thiolase structures, it is seen that in this CHH-thiolase, OAH1 is formed by NE2 of His338 (HDCF) and His388 (GHP). Analysis of the OAH1 hydrogen bond networks suggests that the GHP-histidine is doubly protonated and positively charged in these complexes, whereas the HDCF histidine is neutral and singly protonated.
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Affiliation(s)
- Rajesh K Harijan
- Faculty of Biochemistry and Molecular Medicine, Biocenter Oulu, University of Oulu, FIN-90014, Finland.,Present address: Department of Biochemistry, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
| | - Tiila-Riikka Kiema
- Faculty of Biochemistry and Molecular Medicine, Biocenter Oulu, University of Oulu, FIN-90014, Finland
| | - Shahan M Syed
- Faculty of Biochemistry and Molecular Medicine, Biocenter Oulu, University of Oulu, FIN-90014, Finland
| | - Imran Qadir
- Faculty of Biochemistry and Molecular Medicine, Biocenter Oulu, University of Oulu, FIN-90014, Finland
| | - Muriel Mazet
- Centre de Résonance Magnétique des Systèmes Biologiques (RMSB), UMR5536, Université de Bordeaux, CNRS, 146 rue Léo Saignat, 33076 Bordeaux, France.,Present address: Laboratoire de Microbiologie Fondamentale et Pathogénicité (MFP), UMR5234, Université de Bordeaux, CNRS, 146 rue Léo Saignat, 33076 Bordeaux, France
| | - Frédéric Bringaud
- Centre de Résonance Magnétique des Systèmes Biologiques (RMSB), UMR5536, Université de Bordeaux, CNRS, 146 rue Léo Saignat, 33076 Bordeaux, France.,Present address: Laboratoire de Microbiologie Fondamentale et Pathogénicité (MFP), UMR5234, Université de Bordeaux, CNRS, 146 rue Léo Saignat, 33076 Bordeaux, France
| | - Paul A M Michels
- Centre for Immunity, Infection and Evolution and Centre for Translational and Chemical Biology, School of Biological Sciences, The King's Buildings, The University of Edinburgh, Charlotte Auerbach Road, Edinburgh EH9 3FL, UK
| | - Rik K Wierenga
- Faculty of Biochemistry and Molecular Medicine, Biocenter Oulu, University of Oulu, FIN-90014, Finland
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21
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Li W, Wang Y, Zhu J, Wang Z, Tang G, Huang B. Differential DNA methylation may contribute to temporal and spatial regulation of gene expression and the development of mycelia and conidia in entomopathogenic fungus Metarhizium robertsii. Fungal Biol 2017; 121:293-303. [DOI: 10.1016/j.funbio.2017.01.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Revised: 11/17/2016] [Accepted: 01/17/2017] [Indexed: 12/17/2022]
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22
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Polymorphism and electronic structure of polyimine and its potential significance for prebiotic chemistry on Titan. Proc Natl Acad Sci U S A 2016; 113:8121-6. [PMID: 27382167 DOI: 10.1073/pnas.1606634113] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The chemistry of hydrogen cyanide (HCN) is believed to be central to the origin of life question. Contradictions between Cassini-Huygens mission measurements of the atmosphere and the surface of Saturn's moon Titan suggest that HCN-based polymers may have formed on the surface from products of atmospheric chemistry. This makes Titan a valuable "natural laboratory" for exploring potential nonterrestrial forms of prebiotic chemistry. We have used theoretical calculations to investigate the chain conformations of polyimine (pI), a polymer identified as one major component of polymerized HCN in laboratory experiments. Thanks to its flexible backbone, the polymer can exist in several different polymorphs, which are relatively close in energy. The electronic and structural variability among them is extraordinary. The band gap changes over a 3-eV range when moving from a planar sheet-like structure to increasingly coiled conformations. The primary photon absorption is predicted to occur in a window of relative transparency in Titan's atmosphere, indicating that pI could be photochemically active and drive chemistry on the surface. The thermodynamics for adding and removing HCN from pI under Titan conditions suggests that such dynamics is plausible, provided that catalysis or photochemistry is available to sufficiently lower reaction barriers. We speculate that the directionality of pI's intermolecular and intramolecular =N-H(…)N hydrogen bonds may drive the formation of partially ordered structures, some of which may synergize with photon absorption and act catalytically. Future detailed studies on proposed mechanisms and the solubility and density of the polymers will aid in the design of future missions to Titan.
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23
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Ithayaraja M, Janardan N, Wierenga RK, Savithri HS, Murthy MRN. Crystal structure of a thiolase from Escherichia coli at 1.8 Å resolution. Acta Crystallogr F Struct Biol Commun 2016; 72:534-44. [PMID: 27380370 PMCID: PMC4933003 DOI: 10.1107/s2053230x16008451] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Accepted: 05/25/2016] [Indexed: 11/10/2022] Open
Abstract
Thiolases catalyze the Claisen condensation of two acetyl-CoA molecules to give acetoacetyl-CoA, as well as the reverse degradative reaction. Four genes coding for thiolases or thiolase-like proteins are found in the Escherichia coli genome. In this communication, the successful cloning, purification, crystallization and structure determination at 1.8 Å resolution of a homotetrameric E. coli thiolase are reported. The structure of E. coli thiolase co-crystallized with acetyl-CoA at 1.9 Å resolution is also reported. As observed in other tetrameric thiolases, the present E. coli thiolase is a dimer of two tight dimers and probably functions as a biodegradative enzyme. Comparison of the structure and biochemical properties of the E. coli enzyme with those of other well studied thiolases reveals certain novel features of this enzyme, such as the modification of a lysine in the dimeric interface, the possible oxidation of the catalytic Cys88 in the structure of the enzyme obtained in the presence of CoA and active-site hydration. The tetrameric enzyme also displays an interesting departure from exact 222 symmetry, which is probably related to the deformation of the tetramerization domain that stabilizes the oligomeric structure of the protein. The current study allows the identification of substrate-binding amino-acid residues and water networks at the active site and provides the structural framework required for understanding the biochemical properties as well as the physiological function of this E. coli thiolase.
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Affiliation(s)
- M. Ithayaraja
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, Karnataka 560 012, India
| | - N. Janardan
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, Karnataka 560 012, India
| | - Rik K. Wierenga
- Faculty of Biochemistry and Molecular Medicine, Biocenter Oulu, University of Oulu, FIN-90014 Oulu, Finland
| | - H. S. Savithri
- Biochemistry Department, Indian Institute of Science, Bangalore, Karnataka 560 012, India
| | - M. R. N. Murthy
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, Karnataka 560 012, India
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24
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Nakao N, Kaneda H, Tsushima N, Tanaka M. Characterization of primary structure and post-hatching increase in chicken cytosolic acetoacetyl-coA thiolase in the liver. Poult Sci 2016; 95:1406-10. [PMID: 26944984 DOI: 10.3382/ps/pew045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2015] [Accepted: 12/03/2015] [Indexed: 11/20/2022] Open
Abstract
Acetoacetyl-CoA thiolase (EC 2.3.1.9) catalyzes the cleavage of acetoacetyl-CoA into acetyl-CoA and its reverse reaction, the synthesis of acetoacetyl-CoA. Cytosolic acetoacetyl-CoA thiolase ( CT: ) is a key enzyme in the initial step of the cholesterol synthesis pathway. In the present study, we characterized the amino acid sequence of chicken CT and the tissue distribution of its mRNA and protein, together with their developmental changes in the liver. The amino acid sequence encoded by the nucleotide sequence of chicken CT cDNA showed a higher overall identity with those of human (74.3%) and rat (74.6%) CTs. Amino acid residues known to participate in enzymatic activity in human CT are conserved in chicken CT. Real-time PCR analysis revealed the expression of CT mRNA in the liver, kidney, adrenal gland, jejunum and ovary of adult hens, with higher levels in the liver, kidney, adrenal gland and ovary. Western blot analysis detected an immunoreactive protein of 41 kDa from cytoplasmic fraction but not particulate fractions of adult chicken liver. The immunoreactive protein was detected in all the tissues. The mRNA levels in the liver rapidly increased after hatching, with a maximum on d 5 post-hatching, after which they gradually decreased to adult levels. A similar change was observed in the protein levels. The increase in transcription and protein synthesis of CT suggests that the synthetic pathway of cholesterol from acetyl-CoA produced by CT replaces the hydrolysis of accumulated cholesteryl ester in the liver, in response to a change in the nutrient source from the lipid-rich yolk to a lower-lipid diet during the early post-hatching period.
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Affiliation(s)
- N Nakao
- Laboratory of Animal Physiology, Department of Animal Science, Faculty of Applied Life Science, Nippon Veterinary and Life Science University, 1-7-1 Kyonancho, Musashino, Tokyo, 180-8602, Japan
| | - H Kaneda
- Laboratory of Animal Physiology, Department of Animal Science, Faculty of Applied Life Science, Nippon Veterinary and Life Science University, 1-7-1 Kyonancho, Musashino, Tokyo, 180-8602, Japan
| | - N Tsushima
- Laboratory of Animal Physiology, Department of Animal Science, Faculty of Applied Life Science, Nippon Veterinary and Life Science University, 1-7-1 Kyonancho, Musashino, Tokyo, 180-8602, Japan
| | - M Tanaka
- Laboratory of Animal Physiology, Department of Animal Science, Faculty of Applied Life Science, Nippon Veterinary and Life Science University, 1-7-1 Kyonancho, Musashino, Tokyo, 180-8602, Japan
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25
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Harijan RK, Mazet M, Kiema TR, Bouyssou G, Alexson SEH, Bergmann U, Moreau P, Michels PAM, Bringaud F, Wierenga RK. The SCP2-thiolase-like protein (SLP) of Trypanosoma brucei is an enzyme involved in lipid metabolism. Proteins 2016; 84:1075-96. [PMID: 27093562 DOI: 10.1002/prot.25054] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2015] [Revised: 04/03/2016] [Accepted: 04/08/2016] [Indexed: 11/06/2022]
Abstract
Bioinformatics studies have shown that the genomes of trypanosomatid species each encode one SCP2-thiolase-like protein (SLP), which is characterized by having the YDCF thiolase sequence fingerprint of the Cβ2-Cα2 loop. SLPs are only encoded by the genomes of these parasitic protists and not by those of mammals, including human. Deletion of the Trypanosoma brucei SLP gene (TbSLP) increases the doubling time of procyclic T. brucei and causes a 5-fold reduction of de novo sterol biosynthesis from glucose- and acetate-derived acetyl-CoA. Fluorescence analyses of EGFP-tagged TbSLP expressed in the parasite located the TbSLP in the mitochondrion. The crystal structure of TbSLP (refined at 1.75 Å resolution) confirms that TbSLP has the canonical dimeric thiolase fold. In addition, the structures of the TbSLP-acetoacetyl-CoA (1.90 Å) and TbSLP-malonyl-CoA (2.30 Å) complexes reveal that the two oxyanion holes of the thiolase active site are preserved. TbSLP binds malonyl-CoA tightly (Kd 90 µM), acetoacetyl-CoA moderately (Kd 0.9 mM) and acetyl-CoA and CoA very weakly. TbSLP possesses low malonyl-CoA decarboxylase activity. Altogether, the data show that TbSLP is a mitochondrial enzyme involved in lipid metabolism. Proteins 2016; 84:1075-1096. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Rajesh K Harijan
- Faculty of Biochemistry and Molecular Medicine, Biocenter Oulu, University of Oulu, Oulu, FIN-90014, Finland.,Department of Biochemistry, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York, 10461, USA
| | - Muriel Mazet
- Centre De Résonance Magnétique Des Systèmes Biologiques (RMSB), UMR5536, Université De Bordeaux, CNRS, 146 Rue Léo Saignat, Bordeaux, 33076, France.,Laboratoire De Microbiologie Fondamentale Et Pathogénicité (MFP), UMR5234, Université De Bordeaux, CNRS, 146 Rue Léo Saignat, Bordeaux, 33076, France
| | - Tiila R Kiema
- Faculty of Biochemistry and Molecular Medicine, Biocenter Oulu, University of Oulu, Oulu, FIN-90014, Finland
| | - Guillaume Bouyssou
- Laboratoire De Biogenèse Membranaire, UMR-5200, Université De Bordeaux, CNRS, Bâtiment A3 - 1er Étage, INRA Bordeaux Aquitaine BP81, 71 Avenue Edouard Bourlaux, Villenave D'Ornon Cedex, 33883, France
| | - Stefan E H Alexson
- Karolinska Institutet, Department of Laboratory Medicine, Division of Clinical Chemistry, Karolinska University Hospital, Stockholm, SE 141 86, Sweden
| | - Ulrich Bergmann
- Faculty of Biochemistry and Molecular Medicine, Biocenter Oulu, University of Oulu, Oulu, FIN-90014, Finland
| | - Patrick Moreau
- Laboratoire De Biogenèse Membranaire, UMR-5200, Université De Bordeaux, CNRS, Bâtiment A3 - 1er Étage, INRA Bordeaux Aquitaine BP81, 71 Avenue Edouard Bourlaux, Villenave D'Ornon Cedex, 33883, France
| | - Paul A M Michels
- Centre for Immunity, Infection and Evolution and Centre for Translational and Chemical Biology, School of Biological Sciences, the King's Buildings, University of Edinburgh, Charlotte Auerbach Road, Edinburgh, EH9 3FL, United Kingdom
| | - Frédéric Bringaud
- Centre De Résonance Magnétique Des Systèmes Biologiques (RMSB), UMR5536, Université De Bordeaux, CNRS, 146 Rue Léo Saignat, Bordeaux, 33076, France.,Laboratoire De Microbiologie Fondamentale Et Pathogénicité (MFP), UMR5234, Université De Bordeaux, CNRS, 146 Rue Léo Saignat, Bordeaux, 33076, France
| | - Rik K Wierenga
- Faculty of Biochemistry and Molecular Medicine, Biocenter Oulu, University of Oulu, Oulu, FIN-90014, Finland
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Fogle EJ, Marlier JF, Stillman A, Gao X, Rao Y, Robins LI. An investigation into the butyrylcholinesterase-catalyzed hydrolysis of formylthiocholine using heavy atom kinetic isotope effects. Bioorg Chem 2016; 65:57-60. [DOI: 10.1016/j.bioorg.2016.01.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Revised: 01/26/2016] [Accepted: 01/31/2016] [Indexed: 11/16/2022]
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Fage CD, Meinke JL, Keatinge-Clay AT. Coenzyme A-free activity, crystal structure, and rational engineering of a promiscuous β-ketoacyl thiolase from Ralstonia eutropha. ACTA ACUST UNITED AC 2015; 121:113-121. [PMID: 26494979 DOI: 10.1016/j.molcatb.2015.08.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Thiolases catalyze the formation of carbon-carbon bonds in diverse biosynthetic pathways. The promiscuous β-ketoacyl thiolase B of Ralstonia eutropha (ReBktB) has been utilized in the in vivo conversion of Coenzyme A (CoA)-linked precursors such as acetyl-CoA and glycolyl-CoA into β-hydroxy acids, including the pharmaceutically-important 3,4-dihydroxybutyric acid. Such thiolases could serve as powerful carbon-carbon bond-forming biocatalysts in vitro if handles less costly than CoA were employable. Here, thiolase activity is demonstrated toward substrates linked to the readily-available CoA mimic, N-acetylcysteamine (NAC). ReBktB was observed to catalyze the retro-Claisen condensation of several β-ketoacyl-S-NAC substrates, with a preference for 3-oxopentanoyl-S-NAC over 3-oxobutanoyl-, 3-oxohexanoyl-, and 3-oxoheptanoyl-S-NAC. A 2.0 Å-resolution crystal structure, in which the asymmetric unit consists of four ReBktB tetramers, provides insight into acyl group specificity and how it may be engineered. By replacing an active site methionine with an alanine, a mutant possessing significant activity towards α-methyl substituted, NAC-linked substrates was engineered. The ability of ReBktB and its engineered mutants to utilize NAC-linked substrates will facilitate the in vitro biocatalytic synthesis of diketide chiral building blocks from feedstock molecules such as acetate and propionate.
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Affiliation(s)
- Christopher D Fage
- Department of Molecular Biosciences, The University of Texas, Austin, TX 78712, USA
| | - Jessica L Meinke
- Department of Molecular Biosciences, The University of Texas, Austin, TX 78712, USA
| | - Adrian T Keatinge-Clay
- Department of Molecular Biosciences, The University of Texas, Austin, TX 78712, USA. ; Department of Chemistry, The University of Texas, Austin, TX 78712, USA
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Kim J, Kim KJ. Crystal structure and biochemical characterization of a 3-ketoacyl-CoA thiolase from Ralstoniaeutropha H16. Int J Biol Macromol 2015; 82:425-31. [PMID: 26499087 DOI: 10.1016/j.ijbiomac.2015.10.054] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Revised: 10/14/2015] [Accepted: 10/19/2015] [Indexed: 10/22/2022]
Abstract
The protein ReH16_B0759 from Ralstoniaeutropha is a 3-ketoacyl-coenzyme A (CoA) thiolase that catalyzes the fourth step of the β-oxidation degradative pathways by converting 3-ketoacyl-CoAto acyl-CoA. The crystal structures of ReH16_B0759 in its apo form and as a complex with its CoA substrate have been determined. Although ReH16_B0759 exhibited an overall structure similar to the ReH16_A1887 isozyme, the proteindoes not make a complex for β-oxidation. Similar to other degradative thiolases, ReH16_B0759 functions as a dimer, and the monomer comprises three subdomains. Unlike ReH16_A1887, a substantial structural change was not observed upon the binding of the CoA substrate in ReH16_B0759. Exceptionally, the Arg220 residue moved about 5.00Å to make room for the binding of the adenosine ring. Several charged residues including Arg220 are involved in the stabilization of CoA through hydrogen bond interactions. At the active site of ReH16_B0759, highly conserved residues such as Cys89, His347, and Cys377 were located near the thiol-group of CoA, suggesting that ReH16_B0759 may catalyze the thiolase reaction in a manner similar to that of other degradative thiolases. The residues involved in substrate binding and enzyme catalysis were further confirmed by site-directed mutagenesis.
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Affiliation(s)
- Jieun Kim
- School of Life Sciences, KNU Creative BioResearch Group, Kyungpook National University, Daehak-ro 80, Buk-ku, Daegu 702-701, South Korea
| | - Kyung-Jin Kim
- School of Life Sciences, KNU Creative BioResearch Group, Kyungpook National University, Daehak-ro 80, Buk-ku, Daegu 702-701, South Korea.
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Kim J, Kim KJ. Crystal structure and biochemical properties of ReH16_A1887, the 3-ketoacyl-CoA thiolase from Ralstonia eutropha H16. Biochem Biophys Res Commun 2015; 459:547-52. [PMID: 25749345 DOI: 10.1016/j.bbrc.2015.02.148] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Accepted: 02/25/2015] [Indexed: 11/25/2022]
Abstract
ReH16_A1887 from Ralstonia eutropha is an enzyme annotated as a 3-ketoacyl-CoA thiolase, and it catalyzes the fourth step of β-oxidation degradative pathways by converting 3-ketoacyl-CoA to acyl-CoA. We determined the crystal structures of ReH16_A1887 in the apo-form and in complex with its CoA substrate. ReH16_A1887 functions as a dimer, and the monomer of ReH16_A1887 comprises three subdomains (I, II, and III). The structural comparison between the apo-form and the CoA-bound form revealed that ReH16_A1887 undergoes a structural change in the lid-subdomain (subdomain III) upon the binding of the CoA substrate. The CoA molecule was stabilized by hydrogen bonding with positively charged residues such as Lys18, Arg210, and Arg217, and residues Thr213 and Gln151 aid its binding as well. At the active site of ReH16_A1887, highly conserved residues such as Cys91, His348, and Cys378 were located near the thiol-group of CoA, indicating that ReH16_A1887 might catalyze the thiolase reaction in a way similar to other thiolases. Moreover, in the vicinity of the covalent nucleophile Cys91, a hydrophobic hole that might serve as a binding site for the acyl-group of 3-ketoacyl-CoA was observed. The residues involved in enzyme catalysis and substrate-binding were further confirmed by site-directed mutagenesis experiments.
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Affiliation(s)
- Jieun Kim
- School of Life Sciences, KNU Creative BioResearch Group, Kyungpook National University, Daehak-ro 80, Buk-ku, Daegu 702-701, Republic of Korea
| | - Kyung-Jin Kim
- School of Life Sciences, KNU Creative BioResearch Group, Kyungpook National University, Daehak-ro 80, Buk-ku, Daegu 702-701, Republic of Korea.
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Schaefer CM, Lu R, Nesbitt NM, Schiebel J, Sampson NS, Kisker C. FadA5 a thiolase from Mycobacterium tuberculosis: a steroid-binding pocket reveals the potential for drug development against tuberculosis. Structure 2014; 23:21-33. [PMID: 25482540 DOI: 10.1016/j.str.2014.10.010] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Revised: 09/18/2014] [Accepted: 10/06/2014] [Indexed: 11/29/2022]
Abstract
With the exception of HIV, tuberculosis (TB) is the leading cause of mortality among infectious diseases. The urgent need to develop new antitubercular drugs is apparent due to the increasing number of drug-resistant Mycobacterium tuberculosis (Mtb) strains. Proteins involved in cholesterol import and metabolism have recently been discovered as potent targets against TB. FadA5, a thiolase from Mtb, is catalyzing the last step of the β-oxidation reaction of the cholesterol side-chain degradation under release of critical metabolites and was shown to be of importance during the chronic stage of TB infections. To gain structural and mechanistic insight on FadA5, we characterized the enzyme in different stages of the cleavage reaction and with a steroid bound to the binding pocket. Structural comparisons to human thiolases revealed that it should be possible to target FadA5 specifically, and the steroid-bound structure provides a solid basis for the development of inhibitors against FadA5.
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Affiliation(s)
- Christin M Schaefer
- Rudolf Virchow Center for Experimental Biomedicine, Institute for Structural Biology, University of Würzburg, Josef-Schneider-Strasse 2, 97080 Würzburg, Germany
| | - Rui Lu
- Department of Chemistry, Stony Brook University, Stony Brook, NY 11794-3400, USA
| | - Natasha M Nesbitt
- Department of Chemistry, Stony Brook University, Stony Brook, NY 11794-3400, USA
| | - Johannes Schiebel
- Department of Pharmaceutical Chemistry, University of Marburg, Marbacher Weg 6, 35032 Marburg, Germany
| | - Nicole S Sampson
- Department of Chemistry, Stony Brook University, Stony Brook, NY 11794-3400, USA.
| | - Caroline Kisker
- Rudolf Virchow Center for Experimental Biomedicine, Institute for Structural Biology, University of Würzburg, Josef-Schneider-Strasse 2, 97080 Würzburg, Germany.
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31
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Kiema TR, Harijan RK, Strozyk M, Fukao T, Alexson SEH, Wierenga RK. The crystal structure of human mitochondrial 3-ketoacyl-CoA thiolase (T1): insight into the reaction mechanism of its thiolase and thioesterase activities. ACTA ACUST UNITED AC 2014; 70:3212-25. [PMID: 25478839 DOI: 10.1107/s1399004714023827] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Accepted: 10/28/2014] [Indexed: 11/10/2022]
Abstract
Crystal structures of human mitochondrial 3-ketoacyl-CoA thiolase (hT1) in the apo form and in complex with CoA have been determined at 2.0 Å resolution. The structures confirm the tetrameric quaternary structure of this degradative thiolase. The active site is surprisingly similar to the active site of the Zoogloea ramigera biosynthetic tetrameric thiolase (PDB entries 1dm3 and 1m1o) and different from the active site of the peroxisomal dimeric degradative thiolase (PDB entries 1afw and 2iik). A cavity analysis suggests a mode of binding for the fatty-acyl tail in a tunnel lined by the Nβ2-Nα2 loop of the adjacent subunit and the Lα1 helix of the loop domain. Soaking of the apo hT1 crystals with octanoyl-CoA resulted in a crystal structure in complex with CoA owing to the intrinsic acyl-CoA thioesterase activity of hT1. Solution studies confirm that hT1 has low acyl-CoA thioesterase activity for fatty acyl-CoA substrates. The fastest rate is observed for the hydrolysis of butyryl-CoA. It is also shown that T1 has significant biosynthetic thiolase activity, which is predicted to be of physiological importance.
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Affiliation(s)
- Tiila Riikka Kiema
- Faculty of Biochemistry and Molecular Medicine, Biocenter Oulu, University of Oulu, PO Box 3000, FIN-90014 Oulu, Finland
| | - Rajesh K Harijan
- Faculty of Biochemistry and Molecular Medicine, Biocenter Oulu, University of Oulu, PO Box 3000, FIN-90014 Oulu, Finland
| | - Malgorzata Strozyk
- Karolinska Institutet, Department of Laboratory Medicine, Division of Clinical Chemistry, Karolinska University Hospital, SE-141 86 Stockholm, Sweden
| | - Toshiyuki Fukao
- Department of Pediatrics, Graduate School of Medicine, Gifu University, Yanagido 1-1, Gifu 501-1194, Japan
| | - Stefan E H Alexson
- Karolinska Institutet, Department of Laboratory Medicine, Division of Clinical Chemistry, Karolinska University Hospital, SE-141 86 Stockholm, Sweden
| | - Rik K Wierenga
- Faculty of Biochemistry and Molecular Medicine, Biocenter Oulu, University of Oulu, PO Box 3000, FIN-90014 Oulu, Finland
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32
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Effect of nitrogen and temperature on the transcription of an ACAT gene in Isochrysis galbana. Mol Biol Rep 2014; 41:7235-40. [PMID: 25055977 DOI: 10.1007/s11033-014-3608-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2013] [Accepted: 07/12/2014] [Indexed: 10/25/2022]
Abstract
Thiolases are functionally divided into two groups: 3-ketoacyl-CoA thiolase and acetoacetyl-CoA thiolase (ACAT). Acetoacetyl-CoA thiolase plays a key role in the mevalonate pathway. In this study, a novel gene, IgACAT, which encodes ACAT was cloned from Isochrysis galbana and characterized. The cDNA of IgACAT was 1551 bp in length, consisting of an open reading frame of 1173 bp, a 5' untranslated region of 69 bp and a 3' untranslated region of 309 bp. The deduced amino acid sequence of IgACAT was 390 amino acid residues in length with a predicted molecular weight of 53.59 kDa and an isoelectric point of pH 9.04. The triterpenes content and the expression of IgACAT under nitrogen and temperature stress were analyzed. When I. galbana was treated with excessive nitrogen and at 35 °C, respectively, both the triterpenes content and the abundance of IgACAT gene transcript increased. Our findings will facilitate the regulation of gene expression and genetic modification of the triterpenes synthesis pathway of I. galbana.
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Meiothermus ruber thiolase - a new process stable enzyme for improved butanol synthesis. Biochimie 2014; 103:16-22. [PMID: 24713333 DOI: 10.1016/j.biochi.2014.03.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Accepted: 03/28/2014] [Indexed: 11/20/2022]
Abstract
Butanol is an important renewable building block for the chemical, textile, polymer and biofuels industry due to its increased energy density. Current biotechnological butanol production is a Clostridial based anaerobic fermentation process. Thiolase (EC 2.3.1.9/EC 2.3.1.16) is a key enzyme in this biosynthetic conversion of glucose to butanol. It catalyzes the condensation of two acetyl-CoA molecules, forming acetoacetyl-CoA, which is the first committed step in butanol biosynthesis. The well characterized clostridial thiolases are neither solvent nor thermo stable, which limits butanol yields. We have isolated and characterized a new thermo- (IT50 50 °C = 199 ± 0.1 h) and solvent stable (IS50 > 4%) thiolase derived from the thermophilic bacterium Meiothermus ruber. The observed catalytic constants were Km = 0.07 ± 0.01 mM and kcat = 0.80 ± 0.01 s(-1). In analogy to other thiolases, the enzyme was inhibited by NAD(+) (Ki = 38.7 ± 5.8 mM) and CoA (Ki = 105.1 ± 6.6 μM) but not NADH. The enzyme was stable under harsh process conditions (T = 50 °C, Butanol = 4% v/v) for prolonged time periods (τ = 7 h). The new enzyme provides for targeted in-vivo and in-vitro butanol biosynthesis under industrially relevant process conditions.
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Peterson RM, Huang T, Rudolf JD, Smanski MJ, Shen B. Mechanisms of self-resistance in the platensimycin- and platencin-producing Streptomyces platensis MA7327 and MA7339 strains. ACTA ACUST UNITED AC 2014; 21:389-397. [PMID: 24560608 DOI: 10.1016/j.chembiol.2014.01.005] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Revised: 01/13/2014] [Accepted: 01/15/2014] [Indexed: 01/02/2023]
Abstract
Platensimycin (PTM) and platencin (PTN) are potent inhibitors of bacterial fatty acid synthases and have emerged as promising antibacterial drug leads. We previously characterized the PTM and PTN biosynthetic machineries in the Streptomyces platensis producers. We now identify two mechanisms for PTM and PTN resistance in the S. platensis producers-the ptmP3 or ptnP3 gene within the PTM-PTN or PTN biosynthetic cluster and the fabF gene within the fatty acid synthase locus. PtmP3/PtnP3 and FabF confer PTM and PTN resistance by target replacement and target modification, respectively. PtmP3/PtnP3 also represents an unprecedented mechanism for fatty acid biosynthesis in which FabH and FabF are functionally replaced by a single condensing enzyme. These findings challenge the current paradigm for fatty acid biosynthesis and should be considered in future development of effective therapeutics targeting fatty acid synthase.
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Affiliation(s)
- Ryan M Peterson
- Division of Pharmaceutical Sciences, University of Wisconsin-Madison, Madison, Wisconsin 53705, USA
| | - Tingting Huang
- Department of Chemistry, The Scripps Research Institute, Jupiter, Florida, 33458, USA
| | - Jeffrey D Rudolf
- Department of Chemistry, The Scripps Research Institute, Jupiter, Florida, 33458, USA
| | - Michael J Smanski
- Microbiology Doctoral Training Program, University of Wisconsin-Madison, Madison, Wisconsin 53705, USA
| | - Ben Shen
- Department of Chemistry, The Scripps Research Institute, Jupiter, Florida, 33458, USA.,Department of Molecular Therapeutics, The Scripps Research Institute, Jupiter, Florida 33458, USA.,Natural Products Library Initiative at The Scripps Research Institute, The Scripps Research Institute, Jupiter, Florida 33458, USA
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35
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Robins LI, Meisenheimer KM, Fogle EJ, Chaplan CA, Redman RL, Vacca JT, Tellier MR, Collins BR, Duong DH, Schulz K, Marlier JF. A Kinetic Isotope Effect and Isotope Exchange Study of the Nonenzymatic and the Equine Serum Butyrylcholinesterase-Catalyzed Thioester Hydrolysis. J Org Chem 2013; 78:12029-39. [DOI: 10.1021/jo402063k] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Lori I. Robins
- Department of Chemistry and
Biochemistry, California Polytechnic State University, San Luis Obispo, CA 93407
| | - Kristen M. Meisenheimer
- Department of Chemistry and
Biochemistry, California Polytechnic State University, San Luis Obispo, CA 93407
| | - Emily J. Fogle
- Department of Chemistry and
Biochemistry, California Polytechnic State University, San Luis Obispo, CA 93407
| | - Cory A. Chaplan
- Department of Chemistry and
Biochemistry, California Polytechnic State University, San Luis Obispo, CA 93407
| | - Richard L. Redman
- Department of Chemistry and
Biochemistry, California Polytechnic State University, San Luis Obispo, CA 93407
| | - Joseph T. Vacca
- Department of Chemistry and
Biochemistry, California Polytechnic State University, San Luis Obispo, CA 93407
| | - Michelle R. Tellier
- Department of Chemistry and
Biochemistry, California Polytechnic State University, San Luis Obispo, CA 93407
| | - Brittney R. Collins
- Department of Chemistry and
Biochemistry, California Polytechnic State University, San Luis Obispo, CA 93407
| | - Dorothea H. Duong
- Department of Chemistry and
Biochemistry, California Polytechnic State University, San Luis Obispo, CA 93407
| | - Kathrin Schulz
- Department of Chemistry and
Biochemistry, California Polytechnic State University, San Luis Obispo, CA 93407
| | - John F. Marlier
- Department of Chemistry and
Biochemistry, California Polytechnic State University, San Luis Obispo, CA 93407
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Crystal structures of SCP2-thiolases of Trypanosomatidae, human pathogens causing widespread tropical diseases: the importance for catalysis of the cysteine of the unique HDCF loop. Biochem J 2013; 455:119-30. [PMID: 23909465 DOI: 10.1042/bj20130669] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Thiolases are essential CoA-dependent enzymes in lipid metabolism. In the present study we report the crystal structures of trypanosomal and leishmanial SCP2 (sterol carrier protein, type-2)-thiolases. Trypanosomatidae cause various widespread devastating (sub)-tropical diseases, for which adequate treatment is lacking. The structures reveal the unique geometry of the active site of this poorly characterized subfamily of thiolases. The key catalytic residues of the classical thiolases are two cysteine residues, functioning as a nucleophile and an acid/base respectively. The latter cysteine residue is part of a CxG motif. Interestingly, this cysteine residue is not conserved in SCP2-thiolases. The structural comparisons now show that in SCP2-thiolases the catalytic acid/base is provided by the cysteine residue of the HDCF motif, which is unique for this thiolase subfamily. This HDCF cysteine residue is spatially equivalent to the CxG cysteine residue of classical thiolases. The HDCF cysteine residue is activated for acid/base catalysis by two main chain NH-atoms, instead of two water molecules, as present in the CxG active site. The structural results have been complemented with enzyme activity data, confirming the importance of the HDCF cysteine residue for catalysis. The data obtained suggest that these trypanosomatid SCP2-thiolases are biosynthetic thiolases. These findings provide promise for drug discovery as biosynthetic thiolases catalyse the first step of the sterol biosynthesis pathway that is essential in several of these parasites.
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Fox AR, Soto G, Mozzicafreddo M, Garcia AN, Cuccioloni M, Angeletti M, Salerno JC, Ayub ND. Understanding the function of bacterial and eukaryotic thiolases II by integrating evolutionary and functional approaches. Gene 2013; 533:5-10. [PMID: 24120621 DOI: 10.1016/j.gene.2013.09.096] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2013] [Accepted: 09/26/2013] [Indexed: 10/26/2022]
Abstract
Acetoacetyl-CoA thiolase (EC 2.3.1.9), commonly named thiolase II, condenses two molecules of acetyl-CoA to give acetoacetyl-CoA and CoA. This enzyme acts in anabolic processes as the first step in the biosynthesis of isoprenoids and polyhydroxybutyrate in eukaryotes and bacteria, respectively. We have recently reported the evolutionary and functional equivalence of these enzymes, suggesting that thiolase II could be the rate limiting enzyme in these pathways and presented evidence indicating that this enzyme modulates the availability of reducing equivalents during abiotic stress adaptation in bacteria and plants. However, these results are not sufficient to clarify why thiolase II was evolutionary selected as a critical enzyme in the production of antioxidant compounds. Regarding this intriguing topic, we propose that thiolase II could sense changes in the acetyl-CoA/CoA ratio induced by the inhibition of the tricarboxylic acid cycle under abiotic stress. Thus, the high level of evolutionary and functional constraint of thiolase II may be due to the connection of this enzyme with an ancient and conserved metabolic route.
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Affiliation(s)
- Ana Romina Fox
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Avda. Rivadavia 1917, C1033AAJ Cuidad Autónoma de Buenos Aires, Argentina
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38
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Fang X, Shi L, Ren A, Jiang AL, Wu FL, Zhao MW. The cloning, characterization and functional analysis of a gene encoding an acetyl-CoA acetyltransferase involved in triterpene biosynthesis in Ganoderma lucidum. MYCOSCIENCE 2013. [DOI: 10.1016/j.myc.2012.09.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Mann MS, Lütke-Eversloh T. Thiolase engineering for enhanced butanol production in Clostridium acetobutylicum. Biotechnol Bioeng 2012; 110:887-97. [PMID: 23096577 DOI: 10.1002/bit.24758] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2012] [Revised: 10/01/2012] [Accepted: 10/12/2012] [Indexed: 12/20/2022]
Abstract
Biosynthetic thiolases catalyze the condensation of two molecules acetyl-CoA to acetoacetyl-CoA and represent key enzymes for carbon-carbon bond forming metabolic pathways. An important biotechnological example of such a pathway is the clostridial n-butanol production, comprising various natural constraints that limit titer, yield, and productivity. In this study, the thiolase of Clostridium acetobutylicum, the model organism for solventogenic clostridia, was specifically engineered for reduced sensitivity towards its physiological inhibitor coenzyme A (CoA-SH). A high-throughput screening assay in 96-well microtiter plates was developed employing Escherichia coli as host cells for expression of a mutant thiolase gene library. Screening of this library resulted in the identification of a thiolase derivative with significantly increased activity in the presence of free CoA-SH. This optimized thiolase comprised three amino acid substitutions (R133G, H156N, G222V) and its gene was expressed in C. acetobutylicum ATCC 824 to assess the effect of reduced CoA-SH sensitivity on solvent production. In addition to a clearly delayed ethanol and acetone formation, the ethanol and butanol titers were increased by 46% and 18%, respectively, while the final acetone concentrations were similar to the vector control strain. These results demonstrate that thiolase engineering constitutes a suitable methodology applicable to improve clostridial butanol production, but other biosynthetic pathways involving thiolase-mediated carbon flux limitations might also be subjected to this new metabolic engineering approach.
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Affiliation(s)
- Miriam S Mann
- Abteilung Mikrobiologie, Institut für Biowissenschaften, Universität Rostock, Rostock, Germany
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Goblirsch BR, Frias JA, Wackett LP, Wilmot CM. Crystal structures of Xanthomonas campestris OleA reveal features that promote head-to-head condensation of two long-chain fatty acids. Biochemistry 2012; 51:4138-46. [PMID: 22524624 PMCID: PMC3358466 DOI: 10.1021/bi300386m] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
OleA is a thiolase superfamily enzyme that has been shown to catalyze the condensation of two long-chain fatty acyl-coenzyme A (CoA) substrates. The enzyme is part of a larger gene cluster responsible for generating long-chain olefin products, a potential biofuel precursor. In thiolase superfamily enzymes, catalysis is achieved via a ping-pong mechanism. The first substrate forms a covalent intermediate with an active site cysteine that is followed by reaction with the second substrate. For OleA, this conjugation proceeds by a nondecarboxylative Claisen condensation. The OleA from Xanthomonas campestris has been crystallized and its structure determined, along with inhibitor-bound and xenon-derivatized structures, to improve our understanding of substrate positioning in the context of enzyme turnover. OleA is the first characterized thiolase superfamily member that has two long-chain alkyl substrates that need to be bound simultaneously and therefore uniquely requires an additional alkyl binding channel. The location of the fatty acid biosynthesis inhibitor, cerulenin, that possesses an alkyl chain length in the range of known OleA substrates, in conjunction with a single xenon binding site, leads to the putative assignment of this novel alkyl binding channel. Structural overlays between the OleA homologues, 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) synthase and the fatty acid biosynthesis enzyme FabH, allow assignment of the two remaining channels: one for the thioester-containing pantetheinate arm and the second for the alkyl group of one substrate. A short β-hairpin region is ordered in only one of the crystal forms, and that may suggest open and closed states relevant for substrate binding. Cys143 is the conserved catalytic cysteine within the superfamily, and the site of alkylation by cerulenin. The alkylated structure suggests that a glutamic acid residue (Glu117β) likely promotes Claisen condensation by acting as the catalytic base. Unexpectedly, Glu117β comes from the other monomer of the physiological dimer.
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Affiliation(s)
- Brandon R. Goblirsch
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455
| | - Janice A. Frias
- Department of Biochemistry, Molecular Biology, and Biophysics and BioTechnology Institute, University of Minnesota, St. Paul, Minnesota 55108
| | - Lawrence P. Wackett
- Department of Biochemistry, Molecular Biology, and Biophysics and BioTechnology Institute, University of Minnesota, St. Paul, Minnesota 55108
| | - Carrie M. Wilmot
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455
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Wu D, Wang Q, Assary RS, Broadbelt LJ, Krilov G. A Computational Approach To Design and Evaluate Enzymatic Reaction Pathways: Application to 1-Butanol Production from Pyruvate. J Chem Inf Model 2011; 51:1634-47. [DOI: 10.1021/ci2000659] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Di Wu
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois 60208, United States
| | - Qin Wang
- Department of Chemistry, Boston College, Chestnut Hill, Massachusetts 02467, United States
| | - Rajeev S. Assary
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois 60208, United States
- Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - Linda J. Broadbelt
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois 60208, United States
| | - Goran Krilov
- Department of Chemistry, Boston College, Chestnut Hill, Massachusetts 02467, United States
- Schrödinger, Inc., New York, New York 10036, United States
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Fujii T, Ito K, Katsuma S, Nakano R, Shimada T, Ishikawa Y. Molecular and functional characterization of an acetyl-CoA acetyltransferase from the adzuki bean borer moth Ostrinia scapulalis (Lepidoptera: Crambidae). INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2010; 40:74-78. [PMID: 20043999 DOI: 10.1016/j.ibmb.2009.12.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2009] [Revised: 12/07/2009] [Accepted: 12/09/2009] [Indexed: 05/28/2023]
Abstract
Two types of thiolases are involved in the synthesis and catabolism of fatty acids; acetyl-CoA acetyltransferase (AT) which catalyzes the formation of acetoacetyl-CoA from acetyl-CoA by transferring an acetyl group from one acetyl-CoA molecule to another, and 3-ketoacyl-CoA thiolase which catalyzes a reversible thiolytic cleavage of 3-ketoacyl-CoA into acetyl-CoA and acyl-CoA. Although many mammalian thiolases have been characterized in detail, no thiolases from insects have been functionally characterized to date. Here we report first characterization of an insect AT gene, Osat1, from the pheromone gland of the adzuki bean borer moth Ostrinia scapulalis (Lepidoptera; Crambidae). Osat1 encodes a 41.2 kDa protein comprising 396 amino acid residues (OsAT1), which possesses structural features of the thiolase family. An Osat1 homologue of Bombyx mori (Bmat1) was cloned through exploration of an EST library of the silkworm. Subsequent survey of the genome database revealed that B. mori has at least six Osat1 homologues, among which Bmat1 was most closely related to Osat1. We expressed recombinant OsAT1 using a baculovirus expression system, and verified that OsAT1 catalyzes the formation of acetoacetyl-CoA from acetyl-CoA. Osat1 was expressed in all adult tissues examined. These results indicate that OsAT1 is a functional AT ubiquitously expressed in O. scapulalis tissues.
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Affiliation(s)
- Takeshi Fujii
- Laboratory of Applied Entomology, Graduate School of Agricultural and Life Sciences, University of Tokyo, Tokyo 113-8657, Japan.
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43
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Yang K, Hsieh YH, Kim CK, Zhang H, Wolfe S. Hydration of acetone in the gas phase and in water solvent. CAN J CHEM 2010. [DOI: 10.1139/v09-135] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In water solvent, the hydration of acetone proceeds by a cyclic (cooperative) process in which concurrent C–O bond formation and proton transfer to oxygen take place through a solvent and (or) catalyst bridge. Reactivity is determined primarily by the concentration of a reactant complex and not the barrier from this complex. This situation is reversed in the gas phase; although the concentrations of reactive complexes are much higher than in solution, the barriers are also higher and dominant in determining reactivity. Calculations of isotope effects suggest that multiple hydron transfers are synchronous in the gas phase to avoid zwitterionic transition states. In solution, such transition states are stabilized by solvation and hydron transfers can be asynchronous.
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Affiliation(s)
- Kiyull Yang
- Department of Chemistry, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
- On leave from Department of Chemistry Education, Gyeongsang National University, Jinju 660-701, Korea
- On leave from Department of Chemistry, Inha University, Incheon 402-751, Korea
| | - Yih-Huang Hsieh
- Department of Chemistry, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
- On leave from Department of Chemistry Education, Gyeongsang National University, Jinju 660-701, Korea
- On leave from Department of Chemistry, Inha University, Incheon 402-751, Korea
| | - Chan-Kyung Kim
- Department of Chemistry, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
- On leave from Department of Chemistry Education, Gyeongsang National University, Jinju 660-701, Korea
- On leave from Department of Chemistry, Inha University, Incheon 402-751, Korea
| | - Hui Zhang
- Department of Chemistry, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
- On leave from Department of Chemistry Education, Gyeongsang National University, Jinju 660-701, Korea
- On leave from Department of Chemistry, Inha University, Incheon 402-751, Korea
| | - Saul Wolfe
- Department of Chemistry, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
- On leave from Department of Chemistry Education, Gyeongsang National University, Jinju 660-701, Korea
- On leave from Department of Chemistry, Inha University, Incheon 402-751, Korea
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Hiltunen JK, Chen Z, Haapalainen AM, Wierenga RK, Kastaniotis AJ. Mitochondrial fatty acid synthesis – An adopted set of enzymes making a pathway of major importance for the cellular metabolism. Prog Lipid Res 2010; 49:27-45. [DOI: 10.1016/j.plipres.2009.08.001] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Meriläinen G, Poikela V, Kursula P, Wierenga RK. The thiolase reaction mechanism: the importance of Asn316 and His348 for stabilizing the enolate intermediate of the Claisen condensation. Biochemistry 2009; 48:11011-25. [PMID: 19842716 DOI: 10.1021/bi901069h] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The biosynthetic thiolase catalyzes a Claisen condensation reaction between acetyl-CoA and the enzyme acetylated at Cys89. Two oxyanion holes facilitate this catalysis: oxyanion hole I stabilizes the enolate intermediate generated from acetyl-CoA, whereas oxyanion hole II stabilizes the tetrahedral intermediate of the acetylated enzyme. The latter intermediate is formed when the alpha-carbanion of acetyl-CoA enolate reacts with the carbonyl carbon of acetyl-Cys89, after which C-C bond formation is completed. Oxyanion hole II is made of two main chain peptide NH groups, whereas oxyanion hole I is formed by a water molecule (Wat82) and NE2(His348). Wat82 is anchored in the active site by an optimal set of hydrogen bonding interactions, including a hydrogen bond to ND2(Asn316). Here, the importance of Asn316 and His348 for catalysis has been studied; in particular, the properties of the N316D, N316A, N316H, H348A, and H348N variants have been determined. For the N316D variant, no activity could be detected. For each of the remaining variants, the k(cat)/K(m) value for the Claisen condensation catalysis is reduced by a factor of several hundred, whereas the thiolytic degradation catalysis is much less affected. The crystal structures of the variants show that the structural changes in the active site are minimal. Our studies confirm that oxyanion hole I is critically important for the condensation catalysis. Removing either one of the hydrogen bond donors causes the loss of at least 3.4 kcal/mol of transition state stabilization. It appears that in the thiolytic degradation direction, oxyanion hole I is not involved in stabilizing the transition state of its rate limiting step. However, His348 has a dual role in the catalytic cycle, contributing to oxyanion hole I and activating Cys89. The analysis of the hydrogen bonding interactions in the very polar catalytic cavity shows the importance of two conserved water molecules, Wat82 and Wat49, for the formation of oxyanion hole I and for influencing the reactivity of the catalytic base, Cys378, respectively. Cys89, Asn316, and His348 form the CNH-catalytic triad of the thiolase superfamily. Our findings are also discussed in the context of the importance of this triad for the catalytic mechanism of other enzymes of the thiolase superfamily.
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Affiliation(s)
- Gitte Meriläinen
- Department of Biochemistry, University of Oulu, P.O. Box 3000, 90014 Oulu, Finland
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Klein M, Wenk P, Ansorge-Schumacher M, Fritsch M, Hartmeier W. Heterologous expression and characterisation of a biosynthetic thiolase from Clostridium butyricum DSM 10702. Enzyme Microb Technol 2009. [DOI: 10.1016/j.enzmictec.2009.07.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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47
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Yang W, Di Vizio D, Kirchner M, Steen H, Freeman MR. Proteome scale characterization of human S-acylated proteins in lipid raft-enriched and non-raft membranes. Mol Cell Proteomics 2009; 9:54-70. [PMID: 19801377 DOI: 10.1074/mcp.m800448-mcp200] [Citation(s) in RCA: 222] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Protein S-acylation (palmitoylation), a reversible post-translational modification, is critically involved in regulating protein subcellular localization, activity, stability, and multimeric complex assembly. However, proteome scale characterization of S-acylation has lagged far behind that of phosphorylation, and global analysis of the localization of S-acylated proteins within different membrane domains has not been reported. Here we describe a novel proteomics approach, designated palmitoyl protein identification and site characterization (PalmPISC), for proteome scale enrichment and characterization of S-acylated proteins extracted from lipid raft-enriched and non-raft membranes. In combination with label-free spectral counting quantitation, PalmPISC led to the identification of 67 known and 331 novel candidate S-acylated proteins as well as the localization of 25 known and 143 novel candidate S-acylation sites. Palmitoyl acyltransferases DHHC5, DHHC6, and DHHC8 appear to be S-acylated on three cysteine residues within a novel CCX(7-13)C(S/T) motif downstream of a conserved Asp-His-His-Cys cysteine-rich domain, which may be a potential mechanism for regulating acyltransferase specificity and/or activity. S-Acylation may tether cytoplasmic acyl-protein thioesterase-1 to membranes, thus facilitating its interaction with and deacylation of membrane-associated S-acylated proteins. Our findings also suggest that certain ribosomal proteins may be targeted to lipid rafts via S-acylation, possibly to facilitate regulation of ribosomal protein activity and/or dynamic synthesis of lipid raft proteins in situ. In addition, bioinformatics analysis suggested that S-acylated proteins are highly enriched within core complexes of caveolae and tetraspanin-enriched microdomains, both cholesterol-rich membrane structures. The PalmPISC approach and the large scale human S-acylated protein data set are expected to provide powerful tools to facilitate our understanding of the functions and mechanisms of protein S-acylation.
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Affiliation(s)
- Wei Yang
- Urological Diseases Research Center, Department of Urology, Children's Hospital Boston, Boston, Massachusetts 02115, USA
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Meriläinen G, Schmitz W, Wierenga RK, Kursula P. The sulfur atoms of the substrate CoA and the catalytic cysteine are required for a productive mode of substrate binding in bacterial biosynthetic thiolase, a thioester-dependent enzyme. FEBS J 2008; 275:6136-48. [PMID: 19016856 DOI: 10.1111/j.1742-4658.2008.06737.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Thioesters are more reactive than oxoesters, and thioester chemistry is important for the reaction mechanisms of many enzymes, including the members of the thiolase superfamily, which play roles in both degradative and biosynthetic pathways. In the reaction mechanism of the biosynthetic thiolase, the thioester moieties of acetyl-CoA and the acetylated catalytic cysteine react with each other, forming the product acetoacetyl-CoA. Although a number of studies have been carried out to elucidate the thiolase reaction mechanism at the atomic level, relatively little is known about the factors determining the affinity of thiolases towards their substrates. We have carried out crystallographic studies on the biosynthetic thiolase from Zoogloea ramigera complexed with CoA and three of its synthetic analogues to compare the binding modes of these related compounds. The results show that both the CoA terminal SH group and the side chain SH group of the catalytic Cys89 are crucial for the correct positioning of substrate in the thiolase catalytic pocket. Furthermore, calorimetric assays indicate that the mutation of Cys89 into an alanine significantly decreases the affinity of thiolase towards CoA. Thus, although the sulfur atom of the thioester moiety is important for the reaction mechanism of thioester-dependent enzymes, its specific properties can also affect the affinity and competent mode of binding of the thioester substrates to these enzymes.
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49
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Boekhorst J, Snel B. Identification of homologs in insignificant blast hits by exploiting extrinsic gene properties. BMC Bioinformatics 2007; 8:356. [PMID: 17888146 PMCID: PMC2048517 DOI: 10.1186/1471-2105-8-356] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2007] [Accepted: 09/21/2007] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Homology is a key concept in both evolutionary biology and genomics. Detection of homology is crucial in fields like the functional annotation of protein sequences and the identification of taxon specific genes. Basic homology searches are still frequently performed by pairwise search methods such as BLAST. Vast improvements have been made in the identification of homologous proteins by using more advanced methods that use sequence profiles. However additional improvement could be made by exploiting sources of genomic information other than the primary sequence or tertiary structure. RESULTS We test the hypothesis that extrinsic gene properties gene length and gene order can be of help in differentiating spurious sequence similarity from homology in the gray zone. Sharing gene order and similarity in size dramatically increase the chance of a query-hit pair being homologous: gray zone query-hit pairs of similar size and with conserved gene order are homologous in 99% of all cases, while for query-hit pairs without gene order conservation and with different sizes this is only 55%. CONCLUSION We have shown that using gene length and gene order drastically improves the detection of homologs within the BLAST gray zone. Our findings suggest that the use of such extrinsic gene properties can also improve the performance of homology detection by more advanced methods, and our study thereby underscores the importance of true data integration for fully exploiting genomic information.
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Affiliation(s)
- Jos Boekhorst
- Bioinformatics, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH, The Netherlands
| | - Berend Snel
- Bioinformatics, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH, The Netherlands
- Academic Biomedical Centre, Utrecht University, Yalelaan 1, 3584 CL Utrecht, The Netherlands
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50
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Wu L, Zeng J, Deng G, Guo F, Li N, Liu X, Chu X, Li D. Inactivation of thiolase by 2-alkynoyl-CoA via its intrinsic isomerase activity. Org Lett 2007; 9:3877-80. [PMID: 17764185 DOI: 10.1021/ol0712677] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Selective inactivation of cytosolic thiolase by 2-alkynoyl-CoA via its intrinsic isomerase activity was studied, which provides an example for rationally developing mechanism-based inhibitors based on a side activity of the enzyme, and may become a supplemental method for better treatment of cardiovascular disease and cancer.
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Affiliation(s)
- Long Wu
- Department of Biology and Chemistry, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong SAR, PRC
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