Subunit organization in the TatA complex of the twin arginine protein translocase: a site-directed EPR spin labeling study.

ABSTRACT: The Tat system is used to transport folded proteins across the cytoplasmic membrane in bacteria and archaea and across the thylakoid membrane of plant chloroplasts. Multimers of the integral membrane TatA protein are thought to form the protein-conducting element of the Tat pathway. Nitroxide radicals were introduced at selected positions within the transmembrane helix of Escherichia coli TatA and used to probe the structure of detergent-solubilized TatA complexes by EPR spectroscopy. A comparison of spin label mobilities allowed classification of individual residues as buried within the TatA complex or exposed at the surface and suggested that residues Ile(12) and Val(14) are involved in interactions between helices. Analysis of inter-spin distances suggested that the transmembrane helice

SUBMITTER: White GF 

PROVIDER: S-EPMC2807286 | biostudies-literature | 2010 Jan

REPOSITORIES: biostudies-literature