Identification of vancomycin resistance protein VanA as a D-alanine:D-alanine ligase of altered substrate specificity

Biochemistry. 1991 Feb 26;30(8):2017-21. doi: 10.1021/bi00222a002.

Abstract

High-level glycopeptide resistance in Enterococcus faecium BM4147 is mediated by a 38-kDa protein VanA, whose amino acid sequence is related to Gram-negative D-alanine:D-alanine (D-Ala-D-Ala) ligases [Dutka-Malen, S., Molinas, C., Arthur, M., & Courvalin, P. (1990) Mol. Gen. Genet. 224, 364-372]. We report purification of VanA and demonstrate that it has D-Ala-D-Ala ligase activity but has substantially modified substrate specificity, compared with Gram-negative D-Ala-D-Ala ligases. VanA preferentially condenses D-Ala with D-Met or D-Phe, raising the possibility that its cellular role is to synthesize a modified cell-wall component, which is subsequently not recognized by vancomycin.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Bacterial Proteins / genetics
  • Bacterial Proteins / isolation & purification
  • Bacterial Proteins / metabolism*
  • Carbon-Oxygen Ligases*
  • Chromatography, Gel
  • Drug Resistance, Microbial / physiology
  • Gram-Negative Bacteria / enzymology
  • Molecular Sequence Data
  • Peptide Synthases / genetics
  • Peptide Synthases / isolation & purification
  • Peptide Synthases / metabolism*
  • Streptococcus / drug effects
  • Streptococcus / enzymology*
  • Substrate Specificity
  • Vancomycin / pharmacology*

Substances

  • Bacterial Proteins
  • VanA ligase, Bacteria
  • Vancomycin
  • Carbon-Oxygen Ligases
  • Peptide Synthases
  • D-alanylalanine synthetase