(acyl-carrier-protein) S-malonyltransferase

Class of enzymes [acyl-carrier-protein] S-malonyltransferase bracket Malonyl-CoA:ACP Transacylase 2.3.1.39 37257-17-3 0004314 In enzymology, a [acyl-carrier-protein] S-malonyltransferase (2.3.1.39) is an enzyme that catalyzes the chemical reaction malonyl-CoA + acyl carrier protein CoA + malonyl-[acyl-carrier-protein] Thus, the two substrates of this enzyme are malonyl-CoA and acyl carrier protein, whereas its two products are CoA and malonyl-acyl-carrier-protein. This enzyme belongs to the family of transferases, specifically those acyltransferases transferring groups other than aminoacyl groups. This enzyme participates in fatty acid biosynthesis. Nomenclature The systematic name of this enzyme class is malonyl-CoA:[acyl-carrier-protein] S-malonyltransferase. Other names in common use include malonyl coenzyme A-acyl carrier protein transacylase, 25em [acyl carrier protein]malonyltransferase, FabD, malonyl transacylase, malonyl transferase, malonyl-CoA-acyl carrier protein transacylase, malonyl-CoA:ACP transacylase, malonyl-CoA:AcpM transacylase, malonyl-CoA:acyl carrier protein transacylase, MAT, and MCAT. Structure Crystal Structures of FabD from E.coli Serre L, Verbree EC, Dauter Z, Stuitje AR, Derewenda ZS The Escherichia coli malonyl-CoA:acyl carrier protein transacylase at 1.5-A resolution. Crystal structure of a fatty acid synthase component The Journal of Biological Chemistry 270 22 12961–4 Jun 1995 7768883 10.1074/jbc.270.22.12961 free and Streptomyces coelicolor Keatinge-Clay AT, Shelat AA, Savage DF, Tsai SC, Miercke LJ, O'Connell JD, Khosla C, Stroud RM Catalysis, specificity, and ACP docking site of Streptomyces coelicolor malonyl-CoA:ACP transacylase Structure 11 2 147–54 Feb 2003 12575934 10.1016/s0969-2126(03)00004-2 free are known and provide great insight into the catalytic mechanism of FabD. In E.Coli, FabD primarily involved in FAS pathway. However, in Streptomyces coelicolor, FabD is involved in FAS and polyketide synthase pathways. In both cases, the structures and active sites are very similar. thumb|The crystal structure of (acyl-carrier-protein) S-malonyltransferase (FabD) in E.Coli It is refined at 1.5A resolution to an R factor of 0.19l. The active site is shown in the form of a mesh grid. The protein has an α/β type architecture, but the fold is unique. the active site inferred from the location of the catalytic Ser92 contains a typical nucleophilic elbow as observed in α/ β hydrolases. Serine 92 is hydrogen bonded to His 201 in a fashion similar to various serine hydrolases. however, instead of the carboxylic acid typically found in catalytic triads, the main chain carbonyl of Gln 250 serves as a hydrogen bond acceptor in an interaction with His 201. Two other residues, Arg-117 and Glu-11 are also located in the active site, but their function is not clear. Function The fatty acid synthetic pathway is the principal route for the production of membrane phospholipid acyl chains in bacterial and plants. White SW, Zheng J, Zhang YM The structural biology of type II fatty acid biosynthesis Annual Review of Biochemistry 74 1 791–831 Jun 2005 15952903 10.1146/annurev.biochem.74.082803.133524 The reaction sequence is carried out by a series of individual soluble proteins that are each encoded by a discrete gene, and the pathway intermediates are shuttled between the enzymes. Malony-CoA:ACP Transacylase (FabD) is one such individual soluble protein and catalyzes the following reaction: malonyl-CoA + acyl carrier protein CoA + malonyl-[acyl-carrier-protein] The transfer of malonate to acyl-carrier-protein (ACP) converts the acyl groups into thioester forms which are characteristic of acyl intermediates in fatty acid synthesis and which are strictly required for the condensation reactions catalyzed by β-ketoacyl-ACP synthetase. Ruch FE, Vagelos PR The isolation and general properties of Escherichia coli malonyl coenzyme A-acyl carrier protein transacylase The Journal of Biological Chemistry 248 23 8086–94 Dec 1973 10.1016/S0021-9258(19)43197-9 4584822 free Mechanism Malonyl-CoA:ACP Transacylase uses a ping-pong kinetic mechanism with a bound malonyl ester as the acyl intermediate attached to a serine residue residing within a GHSLG pentapeptide. Ruch FE, Vagelos PR The isolation and general properties of Escherichia coli malonyl coenzyme A-acyl carrier protein transacylase The Journal of Biological Chemistry 248 23 8086–94 Dec 1973 10.1016/S0021-9258(19)43197-9 4584822 free FabD first binds malonyl-CoA, the malonyl moiety is then transferred to the active siteSer 92, and CoA is released from the enzyme. ACP then binds and the malonyl moiety is transferred to the terminal sulfhydryl of the ACP prosthetic group. This reaction is readily reversible. Oefner C, Schulz H, D'Arcy A, Dale GE Mapping the active site of Escherichia coli malonyl-CoA-acyl carrier protein transacylase (FabD) by protein crystallography Acta Crystallographica Section D 62 Pt 6 613–618 Jun 2006 16699188 10.1107/S0907444906009474 thumb|left|300px| FabD reaction occurs via a ping-pong mechanism. In this first step, malonate is transferred from malonyl-coA to Ser 92 in the active site. His201 plays a role in activating Ser92 for nucleophilic attack on the incoming thioester. The CoA-SH functional group is then released from the enzyme and followed by ACP binding thumb|center|300px| His201 activates the thiol of ACP for nucleophilic attack on the malonyl-Ser92 intermediate (generated in the previous step), promoting its transfer to the thiol of ACP Industrial relevance Among all known metabolic pathways in living systems, fatty acid biosynthesis yields the most energy dense products. Liu T, Khosla C Genetic engineering of Escherichia coli for biofuel production Annual Review of Genetics 44 53–69 2010 20822440 10.1146/annurev-genet-102209-163440 As a result, microbial fatty acid derivatives are emerging as a promising renewable energy alternative to fossil fuel derived transportation fuels. Recently, Khosla et al. have devised a procedure to reconstitute E.Coli Fatty Acid Synthase using purified protein components (including FabD) and reported a detailed kinetic analysis of this in-vitro reconstituted system. Yu X, Liu T, Zhu F, Khosla C In vitro reconstitution and steady-state analysis of the fatty acid synthase from Escherichia coli Proceedings of the National Academy of Sciences of the United States of America 108 46 18643–8 Nov 2011 22042840 10.1073/pnas.1110852108 3219124 2011PNAS..10818643Y free Their finding provide a new basis for assessing the scope and limitations of using E.Coli as a biocatalyst for the production of diesel fuels. Clinical relevance FabD as a target for Antibacterial Drug Discovery: An upcoming field Fatty acid biosynthesis is carried out by the ubiquitous Fatty Acid Synthase. Payne DJ, Warren PV, Holmes DJ, Ji Y, Lonsdale JT Bacterial fatty-acid biosynthesis: a genomics-driven target for antibacterial drug discovery Drug Discovery Today 6 10 537–544 May 2001 11369293 10.1016/S1359-6446(01)01774-3 Fatty acid synthase pathways are divided into two distinct molecular forms: Type I and Type II. Rock CO, Cronan JE Escherichia coli as a model for the regulation of dissociable (type II) fatty acid biosynthesis Biochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism 1302 1 1–16 Jul 1996 8695652 10.1016/0005-2760(96)00056-2 In Type I, Fatty Acid Synthase (found in humans and other mammals) is a single large polypeptide composed of several distinct domains. Chirala SS, Huang WY, Jayakumar A, Sakai K, Wakil SJ Animal fatty acid synthase: functional mapping and cloning and expression of the domain I constituent activities Proceedings of the National Academy of Sciences of the United States of America 94 11 5588–93 May 1997 9159116 10.1073/pnas.94.11.5588 20822 1997PNAS...94.5588C free On the other hand, each enzymatic activity (Condensation reaction, Reduction Reaction, Dehydration reaction) is found as a discrete protein in type II systems. Tsay JT, Oh W, Larson TJ, Jackowski S, Rock CO Isolation and characterization of the beta-ketoacyl-acyl carrier protein synthase III gene (fabH) from Escherichia coli K-12 The Journal of Biological Chemistry 267 10 6807–14 Apr 1992 10.1016/S0021-9258(19)50498-7 1551888 free The difference in active site organization and predominance of type II FAS systems in bacteria make the enzymes of this pathway attractive targets for antibacterials. FabD (Acyl-Carrier-Protein S-Malonyltransferase) is a reasonable target given that a high resolution crystal structure is available. However, no FabD inhibitors have been reported in the literature and review articles on this topic. The simple structure and acidity of malonate seem to permit few approaches to synthesizing derivatives (acting as potential inhibitors) that retain the character of the molecule. A second approach for using FabD as a drug target is frequently identified in the literature: FabD can provide a useful tag for locating fab genes because FabD gene is usually adjacent to at least one other fab gene. Campbell JW, Cronan JE Bacterial fatty acid biosynthesis: targets for antibacterial drug discovery Annual Review of Microbiology 55 305–32 2001 11544358 10.1146/annurev.micro.55.1.305 However (as of 2015), no potential drugs have attempted to exploit this feature. References 33em Further reading 33em Alberts AW, Majerus PW, Vagelos PR Acetyl-CoA acyl carrier protein transacylase 1969 Lipids 14 50–53 10.1016/S0076-6879(69)14009-4 Methods in Enzymology 978-0-12-181871-5 Prescott DJ, Vagelos PR Advances in Enzymology and Related Areas of Molecular Biology Acyl carrier protein 36 269–311 1972 4561013 10.1002/9780470122815.ch8 9780470122815 Williamson IP, Wakil SJ Studies on the mechanism of fatty acid synthesis. XVII. Preparation and general properties of acetyl coenzyme A and malonyl coenzyme A-acyl carrier protein transacylases The Journal of Biological Chemistry 241 10 2326–32 May 1966 10.1016/S0021-9258(18)96625-1 5330116 free Joshi VC, Wakil SJ Studies on the mechanism of fatty acid synthesis. XXVI. Purification and properties of malonyl-coenzyme A--acyl carrier protein transacylase of Escherichia coli Archives of Biochemistry and Biophysics 143 2 493–505 Apr 1971 4934182 10.1016/0003-9861(71)90234-7 Kremer L, Nampoothiri KM, Lesjean S, Dover LG, Graham S, Betts J, Brennan PJ, Minnikin DE, Locht C, Besra GS Biochemical characterization of acyl carrier protein (AcpM) and malonyl-CoA:AcpM transacylase (mtFabD), two major components of Mycobacterium tuberculosis fatty acid synthase II The Journal of Biological Chemistry 276 30 27967–74 Jul 2001 11373295 10.1074/jbc.M103687200 free Keatinge-Clay AT, Shelat AA, Savage DF, Tsai SC, Miercke LJ, O'Connell JD, Khosla C, Stroud RM Catalysis, specificity, and ACP docking site of Streptomyces coelicolor malonyl-CoA:ACP transacylase Structure 11 2 147–54 Feb 2003 12575934 10.1016/S0969-2126(03)00004-2 free Szafranska AE, Hitchman TS, Cox RJ, Crosby J, Simpson TJ Kinetic and mechanistic analysis of the malonyl CoA:ACP transacylase from Streptomyces coelicolor indicates a single catalytically competent serine nucleophile at the active site Biochemistry 41 5 1421–7 Feb 2002 11814333 10.1021/bi012001p Biology no Category:EC 2.3.1 Category:Enzymes of known structure Category:Articles containing video clips