Targeting of muralytic enzymes to the cell division site of Gram-positive bacteria: repeat domains direct autolysin to the equatorial surface ring of Staphylococcus aureus

EMBO J. 1998 Aug 17;17(16):4639-46. doi: 10.1093/emboj/17.16.4639.

Abstract

Staphylococcus aureus secretes autolysin (Atl) to complete cell division by hydrolyzing its thick cell wall layer at a designated site, known as the equatorial surface ring. Secreted pro-Atl (1256 amino acids) is cleaved at residues 198 and 775 to generate a pro-peptide, amidase and glucosaminidase, respectively. Here we examined the mechanism that directs amidase and glucosaminidase to the cell division site on the staphylococcal surface. Targeting of pro-Atl to the cell surface occurred prior to its proteolytic processing. Three repeat domains (R1, R2 and R3) located at the center of pro-Atl are necessary and sufficient for the targeting of reporter proteins to the equatorial surface ring. Pro-Atl cleavage at residue 775 separates the polypeptide such that R1 and R2 are linked to the C-terminus of amidase, whereas R3 is located at the N-terminus of glucosaminidase. Thus, it appears that the repeat domains direct pro-Atl, amidase and glucosaminidase to a specific receptor at the equatorial surface ring of staphylococci, thereby allowing localized peptidoglycan hydrolysis and separation of the dividing cells.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Base Sequence
  • Cell Division*
  • DNA Primers
  • Enterotoxins / metabolism
  • Glutathione Transferase / metabolism
  • N-Acetylmuramoyl-L-alanine Amidase / metabolism*
  • Protein Processing, Post-Translational
  • Recombinant Fusion Proteins / metabolism
  • Staphylococcus aureus / cytology
  • Staphylococcus aureus / enzymology*

Substances

  • DNA Primers
  • Enterotoxins
  • Recombinant Fusion Proteins
  • enterotoxin B, staphylococcal
  • Glutathione Transferase
  • N-Acetylmuramoyl-L-alanine Amidase