LambdaSa1 and LambdaSa2 prophage lysins of Streptococcus agalactiae

Academic Article


  • Putative N-acetylmuramyl-L-alanine amidase genes from LambdaSa1 and LambdaSa2 prophages of Streptococcus agalactiae were cloned and expressed in Escherichia coli. The purified enzymes lysed the cell walls of Streptococcus agalactiae, Streptococcus pneumoniae, and Staphylococcus aureus. The peptidoglycan digestion products in the cell wall lysates were not consistent with amidase activity. Instead, the structure of the muropeptide digestion fragments indicated that both the LambdaSa1 and LambdaSa2 lysins exhibited γ-D-glutaminyl-L-lysine endopeptidase activity. The endopeptidase cleavage specificity of the lysins was confirmed using a synthetic peptide substrate corresponding to a portion of the stem peptide and cross bridge of Streptococcus agalactiae peptidoglycan. The LambdaSa2 lysin also displayed β-D-N-acetylglucosaminidase activity. Copyright © 2007, American Society for Microbiology. All Rights Reserved.
  • Authors

    Digital Object Identifier (doi)

    Author List

  • Pritchard DG; Dong S; Kirk MC; Cartee RT; Baker JR
  • Start Page

  • 7150
  • End Page

  • 7154
  • Volume

  • 73
  • Issue

  • 22