Molecular identification of omega-amidase, the enzyme that is functionally coupled with glutamine transaminases, as the putative tumor suppressor Nit2

Biochimie. 2009 Sep;91(9):1066-71. doi: 10.1016/j.biochi.2009.07.002. Epub 2009 Jul 14.

Abstract

Our purpose was to identify the sequence of omega-amidase, which hydrolyses the amide group of alpha-ketoglutaramate, a product formed by glutamine transaminases. In the Bacillus subtilis genome, the gene encoding a glutamine transaminase (mtnV) is flanked by a gene encoding a putative 'carbon-nitrogen hydrolase'. The closest mammalian homolog of this putative bacterial omega-amidase is 'nitrilase 2', whose size and amino acid composition were in good agreement with those reported for purified rat liver omega-amidase. Mouse nitrilase 2 was expressed in Escherichia coli, purified and shown to catalyse the hydrolysis of alpha-ketoglutaramate and other known substrates of omega-amidase. No such activity was observed with mouse nitrilase 1. We conclude that mammalian nitrilase 2 is omega-amidase.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amidohydrolases / chemistry
  • Amidohydrolases / genetics
  • Amidohydrolases / metabolism*
  • Amino Acid Sequence
  • Aminohydrolases / chemistry
  • Aminohydrolases / genetics
  • Aminohydrolases / metabolism*
  • Animals
  • Bacillus subtilis / enzymology
  • Bacillus subtilis / genetics
  • Bacterial Proteins / chemistry
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism*
  • Blotting, Western
  • Cell Line
  • Computational Biology
  • Databases, Genetic
  • Escherichia coli / genetics
  • Escherichia coli / metabolism
  • Genome, Bacterial / genetics
  • Humans
  • Ketoglutaric Acids / metabolism
  • Mice
  • Models, Genetic
  • Molecular Sequence Data
  • Sequence Homology, Amino Acid
  • Transaminases / chemistry
  • Transaminases / genetics
  • Transaminases / metabolism*

Substances

  • Bacterial Proteins
  • Ketoglutaric Acids
  • alpha-ketoglutaramate
  • Transaminases
  • glutamine-pyruvate aminotransferase
  • Amidohydrolases
  • omega-amidase
  • Aminohydrolases