Cloning and expression of the glutamate racemase gene of Bacillus pumilus

J Biochem. 1997 Jun;121(6):1155-61. doi: 10.1093/oxfordjournals.jbchem.a021709.

Abstract

A glutamate racemase gene (murI) was found in Bacillus pumilus cells and cloned into Escherichia coli WM335, a D-glutamate auxotroph, by means of a genetic complement method. MurI of B. pumilus encodes a 272-amino acid protein with an unusual initiation codon, TTG. The deduced amino acid sequence shows significant similarity with those of glutamate racemases from E. coli (ratio of identical residues, 28%), Pediococcus pentosaceus (44%), and Staphylococcus haemolyticus (49%). B. pumilus MurI was expressed as a fusion protein connected to the N-terminal 12 residues of beta-galactosidase; the fusion protein showed glutamate racemase activity, and resembled the enzyme of P. pentosaceus in physicochemical and enzymological properties.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Isomerases / genetics*
  • Amino Acid Sequence
  • Bacillus / genetics*
  • Bacillus subtilis
  • Base Sequence
  • Cloning, Molecular
  • Codon
  • Escherichia coli
  • Gene Expression Regulation, Bacterial / physiology*
  • Gene Expression Regulation, Enzymologic / physiology*
  • Molecular Sequence Data
  • Mutation
  • Peptide Chain Initiation, Translational / genetics
  • Recombinant Fusion Proteins / biosynthesis

Substances

  • Codon
  • Recombinant Fusion Proteins
  • Amino Acid Isomerases
  • glutamate racemase