Identification of the amino acid residues critical for specific binding of the bacteriolytic enzyme of gamma-phage, PlyG, to Bacillus anthracis

Biochem Biophys Res Commun. 2007 Nov 23;363(3):531-5. doi: 10.1016/j.bbrc.2007.09.002. Epub 2007 Sep 11.

Abstract

Bacillus anthracis causes anthrax, a lethal disease affecting humans, which has attracted attention due to its bioterrorism potential. gamma-Phage specifically infects B. anthracis, and is used for its detection. gamma-Phage lysin, PlyG, specifically lyses B. anthracis. Mutational analysis of PlyGB (PlyG binding domain; residues 156-233) indicated that positions 190-199 are necessary for binding to B. anthracis. This region is the central part of PlyGB and is predicted to form a beta-sheet. The amino acid residues of this region are also conserved in other lysins specific for B. anthracis. Alanine substitution at position 190 or 199 within this region resulted in significantly reduced binding, suggesting that L190 and Q199 play key roles in binding of PlyGB to B. anthracis. Our observations provide new insight into the mechanism of specific binding of lysin to B. anthracis, and may be useful in establishing new methods for detection of B. anthracis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Amino Acids / genetics
  • Amino Acids / metabolism*
  • Bacillus Phages / genetics
  • Bacillus Phages / metabolism*
  • Bacillus anthracis / metabolism*
  • Bacillus anthracis / virology
  • Bacteriolysis
  • Binding Sites / genetics
  • Kinetics
  • Molecular Sequence Data
  • Mutagenesis, Site-Directed
  • Mutant Proteins / metabolism
  • Mutation
  • N-Acetylmuramoyl-L-alanine Amidase / genetics
  • N-Acetylmuramoyl-L-alanine Amidase / metabolism*
  • Protein Binding / genetics
  • Sequence Homology, Amino Acid
  • Viral Proteins / genetics
  • Viral Proteins / metabolism*

Substances

  • Amino Acids
  • Mutant Proteins
  • Viral Proteins
  • PlyG lysin, gamma phage
  • N-Acetylmuramoyl-L-alanine Amidase