title: LambdaSa1 and LambdaSa2 prophage lysins of Streptococcus agalactiae.
abstract: 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 gamma-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 beta-d-N-acetylglucosaminidase activity.
authors: Department of Biochemistry & Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL 35294-0005, USA. davidp1@uab.edu
authors: David G
authors: DG
authors: Pritchard
authors: Shengli
authors: S
authors: Dong
authors: Marion C
authors: MC
authors: Kirk
authors: Robert T
authors: RT
authors: Cartee
authors: John R
authors: JR
authors: Baker
mesh_terms: D001433:Bacteriolysis; D020134:Catalytic Domain; D002473:Cell Wall / Q000378:metabolism; D002853:Chromatography, Liquid; D010450:Endopeptidases / Q000378:metabolism; D008401:Gas Chromatography-Mass Spectrometry; D015394:Molecular Structure; D009238:N-Acetylmuramoyl-L-alanine Amidase / Q000235:genetics / Q000378:metabolism*; D010457:Peptidoglycan / Q000737:chemistry / Q000378:metabolism; D039002:Prophages / Q000235:genetics / Q000378:metabolism*; D021241:Spectrometry, Mass, Electrospray Ionization; D013211:Staphylococcus aureus / Q000378:metabolism; D013292:Streptococcus agalactiae / Q000378:metabolism / Q000821:virology*; D013296:Streptococcus pneumoniae / Q000378:metabolism; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D010457:Peptidoglycan; D014764:Viral Proteins; D010450:Endopeptidases; D009238:N-Acetylmuramoyl-L-alanine Amidase