Open AccessFabG, an NADPH-Dependent 3-Ketoacyl Reductase ofPseudomonas aeruginosa, Provides Precursors for Medium-Chain-Length Poly-3-Hydroxyalkanoate Biosynthesis inEscherichia coli
Author(s) -
Qun Ren,
Nicolas Sierro,
Bernard Witholt,
Birgit Kessler
Publication year - 2000
Publication title -
journal of bacteriology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.652
H-Index - 246
eISSN - 1067-8832
pISSN - 0021-9193
DOI - 10.1128/jb.182.10.2978-2981.2000
Subject(s) - escherichia coli , biology , mutant , reductase , biosynthesis , pseudomonas aeruginosa , biochemistry , pseudomonadales , pseudomonas , pseudomonadaceae , microbiology and biotechnology , gene , bacteria , enzyme , genetics
Escherichia coli hosts expressingfabG ofPseudomonas aeruginosa showed 3-ketoacyl coenzyme A (CoA) reductase activity towardR -3-hydroxyoctanoyl-CoA. Furthermore,E. coli recombinants carrying the poly-3-hydroxyalkanoate (PHA) polymerase-encoding genephaC in addition tofabG accumulated medium-chain-length PHAs (mcl-PHAs) from alkanoates. WhenE. coli fadB orfadA mutants, which are deficient in steps downstream or upstream of the 3-ketoacyl-CoA formation step during β-oxidation, respectively, were transformed withfabG , higher levels of PHA were synthesized inE. coli fadA , whereas similar levels of PHA were found inE. coli fadB , compared with those of the corresponding mutants carryingphaC alone. These results strongly suggest that FabG ofP. aeruginosa is able to reduce mcl-3-ketoacyl-CoAs generated by the β-oxidation to 3-hydroxyacyl-CoAs to provide precursors for the PHA polymerase.