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Updated: Jul 15, 2026

Förster Resonance Energy Transfer Mapping: A New Methodology to Elucidate Global Structural Features
Published on: March 16, 2022
Arginine 357 of SecY is needed for SecA-dependent initiation of preprotein translocation
Jeanine de Keyzer1, Anouk Regeling, Arnold J M Driessen
1Department of Molecular Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute and Zernike Institute for Advanced Materials, University of Groningen, Kerklaan 30, 9751 NN Haren, The Netherlands.
Abstract:
The Escherichia coli SecYEG complex forms a transmembrane channel for both protein export and membrane protein insertion. Secretory proteins and large periplasmic domains of membrane proteins require for translocation in addition the SecA ATPase. The conserved arginine 357 of SecY is essential for a yet unidentified step in the SecA catalytic cycle. To further dissect its role, we have analysed the requirement for R357 in membrane protein insertion. Although R357 substitutions abolish post-translational translocation, they allow the translocation of periplasmic domains targeted co-translationally by an N-terminal transmembrane segment. We propose that R357 is essential for the initiation of SecA-dependent translocation only.
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