Identification of the intracellular polyhydroxyalkanoate depolymerase gene of Paracoccus denitrificans and some properties of the gene product.
Paracoccus denitrificans degraded poly(3-hydroxybutyrate) (PHB) in the cells under carbon source starvation. Intracellular poly(3-hydroxyalkanoate) (PHA) depolymerase gene (phaZ) was identified near the PHA synthase gene (phaC) of P. denitrificans. Cell extract of Escherichia coli carrying lacZ--phaZ fusion gene degraded protease-treated PHB granules. Reaction products were thought to be mainly D(--)-3-hydroxybutyrate (3HB) dimer and 3HB oligomer. Diisopropylfluorophosphonate and Triton X-100 exhibited an inhibitory effect on the degradation of PHB granules. When cell extract of the recombinant E. coli was used, Mg(2+) ion inhibited PHB degradation. However, the inhibitory effect by Mg(2+) ion was not observed using the cell extract of P. denitrificans.
Gao
D
D
Departmentof Bioproductive Science, Faculty of Agriculture, Utsunomiya University, Japan.
Maehara
A
A
Yamane
T
T
Ueda
S
S
D000595:Amino Acid Sequence; D001483:Base Sequence; D001673:Biodegradation, Environmental; D002265:Carboxylic Ester Hydrolases / Q000235:genetics* / Q000302:isolation & purification; D003001:Cloning, Molecular; D004269:DNA, Bacterial; D004926:Escherichia coli; D005798:Genes, Bacterial; D006885:Hydroxybutyrates / Q000378:metabolism; D007202:Indicators and Reagents; D008274:Magnesium / Q000378:metabolism; D008969:Molecular Sequence Data; D010231:Paracoccus denitrificans / Q000201:enzymology* / Q000235:genetics; D011091:Polyesters / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism
D004269:DNA, Bacterial; D006885:Hydroxybutyrates; D007202:Indicators and Reagents; D011091:Polyesters; D011994:Recombinant Proteins; D002265:Carboxylic Ester Hydrolases; C077226:poly(3-hydroxyalkanoic acid) depolymerase; D008274:Magnesium