Abstract
Genetic approaches can address the question of how integral membrane Sec factors interact with each other and facilitate protein translocation across the cytoplasmic membrane of E. coli. This review summarizes genetic analyses of SecY, SecE and some other protein translocation factors, utilizing ‘prl’ mutations,‘sec’ mutations, ‘suppressor-directed inactivation’, ‘Sec titration’, dominant negative mutations and their suppressors. Evidence suggests that coordinate participation of SecY, SecE, SecD, SecF, and probably some other factors, is crucial for the process.