Defining the solution state dimer structure of Escherichia coli SecA using Forster resonance energy transfer.

ABSTRACT: The Sec machinery constitutes the major pathway for protein translocation in bacteria. SecA is thought to act as a molecular motor driving translocation of the preprotein across the membrane by repeated ATP-driven cycles of insertion and retraction at the translocon channel. SecA is predominately a dimer under physiological conditions; however, its oligomeric state during active protein translocation is still unresolved. Five SecA crystal structures have been determined, each displaying a different dimer interface, suggesting that SecA may adopt different dimer configurations. In this study, a Förster resonance energy transfer approach was utilized with nine functional monocysteine SecA mutants labeled with appropriate dyes to determine the predominant solution state dimer. Three different

SUBMITTER: Auclair SM 

PROVIDER: S-EPMC3717379 | biostudies-literature | 2013 Apr

REPOSITORIES: biostudies-literature