Sequence of the bphD gene encoding 2-hydroxy-6-oxo-(phenyl/chlorophenyl)hexa-2,4-dienoic acid (HOP/cPDA) hydrolase involved in the biphenyl/polychlorinated biphenyl degradation pathway in Comamonas testosteroni: evidence suggesting involvement of Ser112 in catalytic activity

Gene. 1995 Apr 14;156(1):69-74. doi: 10.1016/0378-1119(95)00073-f.

Abstract

The nucleotide sequence of bphD, encoding 2-hydroxy-6-oxo-(phenyl/chlorophenyl)hexa-2,4-dienoic acid hydrolase involved in the biphenyl/polychlorinated biphenyl degradation pathway of Comamonas testosteroni strain B-356, was determined. Comparison of the deduced amino-acid sequence with published sequences led to the identification of a 'lipase box', containing a consensus pentapeptide sequence GlyXaaSerXaaGly. This suggested that the mechanism of action of this enzyme may involve an Asp-Ser-His catalytic triad similar to that of classical lipases and serine hydrolases. Further biochemical and genetic evidence for the active-site involvement of Ser112 was obtained by showing that a semipurified enzyme was inhibited by PMSF, a classic inhibitor of serine hydrolases, and by site-directed Ser112-->Ala mutagenesis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Base Sequence
  • Binding Sites
  • Biphenyl Compounds / metabolism*
  • Genes, Bacterial / genetics*
  • Gram-Negative Aerobic Bacteria / enzymology
  • Gram-Negative Aerobic Bacteria / genetics*
  • Hydrolases / genetics*
  • Hydrolases / metabolism
  • Molecular Sequence Data
  • Mutation / physiology
  • Polychlorinated Biphenyls / metabolism
  • Sequence Alignment
  • Sequence Analysis, DNA
  • Sequence Homology, Amino Acid
  • Sequence Homology, Nucleic Acid
  • Serine / physiology*

Substances

  • Biphenyl Compounds
  • diphenyl
  • Serine
  • Polychlorinated Biphenyls
  • Hydrolases
  • 2,6-dioxo-6-phenylhexa-3-enoate hydrolase

Associated data

  • GENBANK/L34338