Distribution of protein A on the surface of Staphylococcus aureus

J Bacteriol. 2007 Jun;189(12):4473-84. doi: 10.1128/JB.00227-07. Epub 2007 Apr 6.

Abstract

Surface proteins of Staphylococcus aureus fulfill many important roles during the pathogenesis of human infections and are anchored to the cell wall envelope by sortases. Although the chemical linkage of proteins to cell wall cross bridges is known, the mechanisms whereby polypeptides are distributed on the staphylococcal surface have not been revealed. We show here that protein A, the ligand of immunoglobulin, is unevenly distributed over the staphylococcal surface. Upon removal with trypsin, newly synthesized polypeptide is deposited at two to four discrete foci. During subsequent growth, protein A appears to be slowly distributed from these sites. When viewed through multiple focal planes by laser scanning microscopy, protein A foci are arranged in a circle surrounding the bacterial cell. This pattern of distribution requires the LPXTG sorting signal of protein A as well as sortase A, the transpeptidase that anchors polypeptides to cell wall cross bridges. A model is presented whereby protein A deposition at discrete sites coupled with cell wall synthesis enables distribution of protein A on the staphylococcal surface.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Aminoacyltransferases / genetics
  • Bacterial Proteins / genetics
  • Cell Wall / chemistry*
  • Cell Wall / metabolism
  • Cysteine Endopeptidases / genetics
  • Microscopy, Confocal
  • Mutation
  • Protein Sorting Signals
  • Staphylococcal Protein A / analysis*
  • Staphylococcal Protein A / genetics
  • Staphylococcus aureus / chemistry*
  • Staphylococcus aureus / genetics
  • Staphylococcus aureus / metabolism
  • Trypsin / metabolism

Substances

  • Bacterial Proteins
  • Protein Sorting Signals
  • Staphylococcal Protein A
  • Aminoacyltransferases
  • sortase A
  • Trypsin
  • Cysteine Endopeptidases