Type I Signal Peptidases of Gram-positive Bacteria

Biochim Biophys Acta. 2004 Nov 11;1694(1-3):279-97. doi: 10.1016/j.bbamcr.2004.05.006.


Proteins that are exported from the cytoplasm to the periplasm and outer membrane of Gram-negative bacteria, or the cell wall and growth medium of Gram-positive bacteria, are generally synthesized as precursors with a cleavable signal peptide. During or shortly after pre-protein translocation across the cytoplasmic membrane, the signal peptide is removed by signal peptidases. Importantly, pre-protein processing by signal peptidases is essential for bacterial growth and viability. This review is focused on the signal peptidases of Gram-positive bacteria, Bacillus and Streptomyces species in particular. Evolutionary concepts, current knowledge of the catalytic mechanism, substrate specificity requirements and structural aspects are addressed. As major insights in signal peptidase function and structure have been obtained from studies on the signal peptidase LepB of Escherichia coli, similarities and differences between this enzyme and known Gram-positive signal peptidases are highlighted. Notably, while the incentive for previous research on Gram-positive signal peptidases was largely based on their role in the biotechnologically important process of protein secretion, present-day interest in these essential enzymes is primarily derived from the idea that they may serve as targets for novel anti-microbials.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Bacterial Proteins / metabolism*
  • Gram-Positive Bacteria / enzymology*
  • Gram-Positive Bacteria / physiology
  • Membrane Proteins / genetics
  • Membrane Proteins / physiology*
  • Phylogeny
  • Protein Conformation
  • Protein Transport / physiology
  • Serine Endopeptidases / genetics
  • Serine Endopeptidases / physiology*


  • Bacterial Proteins
  • Membrane Proteins
  • Serine Endopeptidases
  • type I signal peptidase