A family of bacteriocin ABC transporters carry out proteolytic processing of their substrates concomitant with export

Mol Microbiol. 1995 Apr;16(2):229-40. doi: 10.1111/j.1365-2958.1995.tb02295.x.


Lantibiotic and non-lantibiotic bacteriocins are synthesized as precursor peptides containing N-terminal extensions (leader peptides) which are cleaved off during maturation. Most non-lantibiotics and also some lantibiotics have leader peptides of the so-called double-glycine type. These leader peptides share consensus sequences and also a common processing site with two conserved glycine residues in positions -1 and -2. The double-glycine-type leader peptides are unrelated to the N-terminal signal sequences which direct proteins across the cytoplasmic membrane via the sec pathway. Their processing sites are also different from typical signal peptidase cleavage sites, suggesting that a different processing enzyme is involved. Peptide bacteriocins are exported across the cytoplasmic membrane by a dedicated ATP-binding cassette (ABC) transporter. Here we show that the ABC transporter is the maturation protease and that its proteolytic domain resides in the N-terminal part of the protein. This result demonstrates that the ABC transporter has a dual function: (i) removal of the leader peptide from its substrate, and (ii) translocation of its substrate across the cytoplasmic membrane. This represents a novel strategy for secretion of bacterial proteins.

Publication types

  • Comparative Study

MeSH terms

  • ATP-Binding Cassette Transporters / genetics
  • ATP-Binding Cassette Transporters / metabolism*
  • Amino Acid Sequence
  • Bacteriocins / biosynthesis
  • Bacteriocins / genetics
  • Bacteriocins / metabolism*
  • Base Sequence
  • Biological Transport
  • Conserved Sequence
  • Escherichia coli / metabolism
  • Genes, Bacterial
  • Molecular Sequence Data
  • Point Mutation
  • Protein Precursors / biosynthesis
  • Protein Precursors / genetics
  • Protein Sorting Signals / metabolism
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • Sequence Alignment
  • Sequence Homology, Amino Acid
  • Substrate Specificity
  • Transcriptional Activation


  • ATP-Binding Cassette Transporters
  • Bacteriocins
  • LagA protein, Lactococcus lactis
  • Protein Precursors
  • Protein Sorting Signals
  • Recombinant Proteins
  • lactococcin A