title: Establishing a toolkit for precursor-directed polyketide biosynthesis: exploring substrate promiscuities of acid-CoA ligases.
abstract: Polyketides are chemically diverse and medicinally important biochemicals that are biosynthesized from acyl-CoA precursors by polyketide synthases. One of the limitations to combinatorial biosynthesis of polyketides has been the lack of a toolkit that describes the means of delivering novel acyl-CoA precursors necessary for polyketide biosynthesis. Using five acid-CoA ligases obtained from various plants and microorganisms, we biosynthesized an initial library of 79 acyl-CoA thioesters by screening each of the acid-CoA ligases against a library of 123 carboxylic acids. The library of acyl-CoA thioesters includes derivatives of cinnamyl-CoA, 3-phenylpropanoyl-CoA, benzoyl-CoA, phenylacetyl-CoA, malonyl-CoA, saturated and unsaturated aliphatic CoA thioesters, and bicyclic aromatic CoA thioesters. In our search for the biosynthetic routes of novel acyl-CoA precursors, we discovered two previously unreported malonyl-CoA derivatives (3-thiophenemalonyl-CoA and phenylmalonyl-CoA) that cannot be produced by canonical malonyl-CoA synthetases. This report highlights the utility and importance of determining substrate promiscuities beyond conventional substrate pools and describes novel enzymatic routes for the establishment of precursor-directed combinatorial polyketide biosynthesis.
authors.affiliation: Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597.
authors.forename: Maybelle Kho
authors.initials: MK
authors.lastname: Go
authors.forename: Jeng Yeong
authors.initials: JY
authors.lastname: Chow
authors.forename: Vivian Wing Ngar
authors.initials: VW
authors.lastname: Cheung
authors.forename: Yan Ping
authors.initials: YP
authors.lastname: Lim
authors.forename: Wen Shan
authors.initials: WS
authors.lastname: Yew
mesh_terms: D000214:Acyl Coenzyme A / Q000737:chemistry / Q000378:metabolism*; D001419:Bacteria / Q000201:enzymology* / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D002264:Carboxylic Acids / Q000737:chemistry / Q000378:metabolism; D003001:Cloning, Molecular; D003066:Coenzyme A Ligases / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D004952:Esters / Q000737:chemistry / Q000378:metabolism; D008958:Models, Molecular; D012275:Oryza / Q000201:enzymology / Q000235:genetics; D010944:Plants / Q000201:enzymology* / Q000235:genetics; D048630:Polyketide Synthases / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D061065:Polyketides / Q000737:chemistry / Q000378:metabolism*; D012231:Rhizobium / Q000201:enzymology / Q000235:genetics; D048372:Streptomyces coelicolor / Q000201:enzymology / Q000235:genetics; D013379:Substrate Specificity
chemical_list: D000214:Acyl Coenzyme A; D001426:Bacterial Proteins; D002264:Carboxylic Acids; D004952:Esters; D061065:Polyketides; D048630:Polyketide Synthases; D003066:Coenzyme A Ligases; C021533:malonyl-CoA synthetase; C023914:phenylacetate - CoA ligase