Molecular characterization and properties of (R)-specific enoyl-CoA hydratases from Pseudomonas aeruginosa: metabolic tools for synthesis of polyhydroxyalkanoates via fatty acid ß-oxidation

摘要: Abstract The use of (R)-specific enoyl-coenzyme A (CoA) hydratase (PhaJ) provides a powerful tool for polyhydroxyalkanoate (PHA) synthesis from fatty acids or plant oils in recombinant bacteria. PhaJ monomer units PHA the acid s-oxidation cycle. Previously, two phaJ genes (phaJ1Pa and phaJ2Pa) were identified Pseudomonas aeruginosa. This report identifies new (phaJ3Pa phaJ4Pa) P. aeruginosa through genomic database search. abilities four PhaJPa proteins (R)-3-hydroxyacyl-acyl carrier protein [(R)-3HA-ACP] dehydrases, FabAPa FabZPa, to supply monomers enoyl-CoA substrates determined. presence either PhaJ1Pa PhaJ4Pa Escherichia coli led high levels accumulation (as as 36–41 wt.% dry cells) consisting mainly short- (C4–C6) medium-chain-length (C6–C10) 3HA units, respectively. Furthermore, detailed characterizations performed using purified samples. Kinetic analysis revealed that only exhibits almost constant maximum reaction rates (Vmax) irrespective chain length substrates. assay stereospecific hydration that, unlike PhaJ1Pa, has relatively low (R)-specificity. These hydratases may be very useful monomer-suppliers designed PHAs