Arginine 357 of SecY is needed for SecA-dependent initiation of preprotein translocation.
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.
de Keyzer
Jeanine
J
Department 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.
Regeling
Anouk
A
Driessen
Arnold J M
AJ
D000251:Adenosine Triphosphatases / Q000502:physiology*; D019943:Amino Acid Substitution; D001120:Arginine / Q000235:genetics / Q000502:physiology*; D001426:Bacterial Proteins / Q000502:physiology*; D002462:Cell Membrane / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000737:chemistry / Q000235:genetics*; D008565:Membrane Proteins / Q000378:metabolism; D026901:Membrane Transport Proteins / Q000502:physiology*; D009154:Mutation; D011498:Protein Precursors / Q000378:metabolism*; D021381:Protein Transport / Q000235:genetics; D000069816:SEC Translocation Channels; D000081416:SecA Proteins
D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D011498:Protein Precursors; D000069816:SEC Translocation Channels; C057841:SecY protein, E coli; D001120:Arginine; D000251:Adenosine Triphosphatases; D000081416:SecA Proteins