Mapping of the signal peptide-binding domain of Escherichia coli SecA using Forster resonance energy transfer.

ABSTRACT: Identification of the signal peptide-binding domain within SecA ATPase is an important goal for understanding the molecular basis of SecA preprotein recognition as well as elucidating the chemo-mechanical cycle of this nanomotor during protein translocation. In this study, Forster resonance energy transfer methodology was employed to map the location of the SecA signal peptide-binding domain using a collection of functional monocysteine SecA mutants and alkaline phosphatase signal peptides labeled with appropriate donor-acceptor fluorophores. Fluorescence anisotropy measurements yielded an equilibrium binding constant of 1.4 or 10.7 muM for the alkaline phosphatase signal peptide labeled at residue 22 or 2, respectively, with SecA, and a binding stoichiometry of one signal peptide bound pe

SUBMITTER: Auclair SM 

PROVIDER: S-EPMC2850574 | biostudies-literature | 2010 Feb

REPOSITORIES: biostudies-literature