We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Proteolytic processing of Escherichia coli twin-arginine signal peptides by LepB.
- Authors
Lüke, Iris; Handford, Jennifer I; Palmer, Tracy; Sargent, Frank
- Abstract
The twin-arginine translocation (Tat) apparatus is a protein targeting system found in the cytoplasmic membranes of many prokaryotes. Substrate proteins of the Tat pathway are synthesised with signal peptides bearing SRRxFLK 'twin-arginine' amino acid motifs. All Tat signal peptides have a common tripartite structure comprising a polar N-terminal region, followed by a hydrophobic region of variable length and a polar C-terminal region. In Escherichia coli, Tat signal peptides are proteolytically cleaved after translocation. The signal peptide C-terminal regions contain conserved AxA motifs, which are possible recognition sequences for leader peptidase I (LepB). In this work, the role of LepB in Tat signal peptide processing was addressed directly. Deliberate repression of lepB expression prevented processing of all Tat substrates tested, including SufI, AmiC, and a TorA-23K reporter protein. In addition, electron microscopy revealed gross defects in cell architecture and membrane integrity following depletion of cellular LepB protein levels.
- Publication
Archives of microbiology, 2009, Vol 191, Issue 12, p919
- ISSN
1432-072X
- Publication type
Journal Article
- DOI
10.1007/s00203-009-0516-5