Most secreted proteins are synthesized as 'preproteins' with amino-terminal, cleavable signal peptides which mediate targeting and translocation across membranes by translocases. The main bacterial translocase comprises the SecYEG protein-conducting channel and the peripheral ATPase motor SecA. Signal peptides, thought to be involved in preprotein targeting to SecA, are now shown to have a new role beyond targeting as allosteric activators of the translocase.
- Giorgos Gouridis
- Spyridoula Karamanou
- Anastassios Economou
