Cloning and characterization of poly(3-hydroxybutyrate) biosynthesis genes from Pseudomonas sp. USM 4-55.
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).
Tan
Yifen
Y
School of Biological Sciences, Universiti Sains Malaysia, 11800 Penang, Malaysia.
Neo
Pei-Chin
PC
Najimudin
Nazalan
N
Sudesh
Kumar
K
Muhammad
Tengku Sifzizul Tengku
TS
Othman
Ahmad Sofiman
AS
Samian
Razip
R
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
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