The secY protein can act post-translationally to promote bacterial protein export

R. Bacallao, E. Crooke, K. Shiba, W. Wickner, K. Ito

Research output: Contribution to journalArticle

18 Scopus citations


Conditionally lethal Escherichia coli mutants in secY (prlA) show defective export of proteins to the periplasm and outer membrane. It has been proposed that this gene and other sec genes must act on pro-OmpA at an early stage of protein synthesis in order to allow later translocation to occur. We have described a temperature-sensitive mutation in which the secY(ts) function is impaired at the nonpermissive temperature (Ito, K. (1984) Mol. Gen. Genet. 197, 204-208). A plasmid bearing the wild-type secY gene under the control of the lactose operon (Shiba, K. Ito, K., Yura, T., and Cerretti, D.P. (1984) EMBO J. 3, 631-635) has been introduced into this mutant strain. We now report that the in vivo chase of pulse-labeled full length pro-OmpA to mature OmpA is accelerated by inducing the synthesis of the wild-type secY protein at the end of the period of pulse labeling. We have also assayed the requirements for secY function for in vitro protein translocation. Membranes derived from secY ts cells which were incubated at 42°C were inactive in vitro in the post-translational uptake and processing of pro-OmpA. Thus, the secY protein can act post-translationally, enhancing the translocation of completed pro-OmpA polypeptide chains across the plasma membrane.

Original languageEnglish (US)
Pages (from-to)12907-12910
Number of pages4
JournalJournal of Biological Chemistry
Issue number27
StatePublished - Dec 1 1986
Externally publishedYes

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology

Fingerprint Dive into the research topics of 'The secY protein can act post-translationally to promote bacterial protein export'. Together they form a unique fingerprint.

  • Cite this