Charged amino acids in a preprotein inhibit SecA-dependent protein translocation.Nouwen, N. P., Berrelkamp, G. & Driessen, A. J. M., 6-Mar-2009, In : Journal of Molecular Biology. 386, 4, p. 1000-1010 11 p.
Research output: Contribution to journal › Article › Academic › peer-review
Sec translocase catalyzes membrane protein insertion and translocation. We have introduced stretches of charged amino acid residues into the preprotein proOmpA and have analyzed their effect on in vitro protein translocation into Escherichia coli inner membrane vesicles. Both negatively and positively charged amino acid residues inhibit translocation of proOmpA, yielding a partially translocated polypeptide chain that blocks the translocation site and no longer activates preprotein-stimulated SecA ATPase activity. Stretches of positively charged residues are much stronger translocation inhibitors and suppressors of the preprotein-stimulated SecA ATPase activity than negatively charged residues. These results indicate that both clusters of positively and negatively charged amino acids are poor substrates for the Sec translocase and that this is reflected by their inability to stimulate the ATPase activity of SecA. (C) 2009 Elsevier Ltd. All rights reserved.
|Number of pages||11|
|Journal||Journal of Molecular Biology|
|Publication status||Published - 6-Mar-2009|
- SecA, SecYEG, proOmpA, translocation, PROTON MOTIVE FORCE, EVERTED MEMBRANE-VESICLES, ESCHERICHIA-COLI, CYTOPLASMIC MEMBRANE, STEPWISE MOVEMENT, CATALYTIC CYCLE, RESIDUES, EXPORT, ATP, SECDFYAJC