title: Cloning and characterization of poly(3-hydroxybutyrate) biosynthesis genes from Pseudomonas sp. USM 4-55.
abstract: Pseudomonas sp. USM 4-55 is a locally isolated bacterium that possesses the ability to produce polyhydroxyalkanoates (PHA) consisting of both poly(3-hydroxybutyrate) [P(3HB)] homopolymer and medium-chain length (mcl) monomers (6 to 14 carbon atoms) when sugars or fatty acids are utilized as the sole carbon source. In this study, the P(3HB) biosynthesis operon carrying the phbC(Ps) P(3HB) synthase was successfully cloned and sequenced using a homologous probe. Three open reading frames encoding NADPH-dependent acetoacetyl-coenzyme A reductase (PhbB(Ps)), beta-ketothiolase (PhbA(Ps)) and P(3HB) synthase (PhbC(Ps)) were found in the phb operon. The genetic organization of phb operon showed a putative promoter region, followed by phbB(Ps)-phbA(Ps)-phbC(Ps). phbR(Ps)which encoded a putative transcriptional activator was located in the opposite orientation, upstream of phbBAC(Ps). Heterologous expression of pGEM''ABex harboring phbC(Ps) in Escherichia coli JM109 resulted in P(3HB) accumulation of up to 40% of dry cell weight (DCW).
authors.affiliation: School of Biological Sciences, Universiti Sains Malaysia, 11800 Penang, Malaysia.
authors.forename: Yifen
authors.initials: Y
authors.lastname: Tan
authors.forename: Pei-Chin
authors.initials: PC
authors.lastname: Neo
authors.forename: Nazalan
authors.initials: N
authors.lastname: Najimudin
authors.forename: Kumar
authors.initials: K
authors.lastname: Sudesh
authors.forename: Tengku Sifzizul Tengku
authors.initials: TS
authors.lastname: Muhammad
authors.forename: Ahmad Sofiman
authors.initials: AS
authors.lastname: Othman
authors.forename: Razip
authors.initials: R
authors.lastname: Samian
mesh_terms: D000102:Acetyl-CoA C-Acyltransferase / Q000235:genetics; D000217:Acyltransferases / Q000235:genetics; D000429:Alcohol Oxidoreductases / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics; D053898:Biosynthetic Pathways / Q000235:genetics*; D050260:Carbohydrate Metabolism; D002244:Carbon / Q000378:metabolism; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004742:Enhancer Elements, Genetic; D004926:Escherichia coli / Q000235:genetics; D005227:Fatty Acids / Q000378:metabolism; D023061:Gene Order; D005798:Genes, Bacterial; D006885:Hydroxybutyrates / Q000378:metabolism*; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D009876:Operon; D011091:Polyesters / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D011549:Pseudomonas / Q000235:genetics* / Q000378:metabolism*; D017422:Sequence Analysis, DNA; D000094122:Polyhydroxybutyrates
chemical_list: D000102:Acetyl-CoA C-Acyltransferase; D000217:Acyltransferases; D000429:Alcohol Oxidoreductases; D001426:Bacterial Proteins; D002244:Carbon; D004269:DNA, Bacterial; D005227:Fatty Acids; D006885:Hydroxybutyrates; D011091:Polyesters; C003182:poly-beta-hydroxybutyrate; D000094122:Polyhydroxybutyrates; C023744:acetoacetyl-CoA reductase; C060970:poly-beta-hydroxybutyrate polymerase