Escherichia coli YidC is a membrane insertase for Sec-independent proteins

EMBO J. 2004 Jan 28;23(2):294-301. doi: 10.1038/sj.emboj.7600063. Epub 2004 Jan 22.


YidC is a recently discovered bacterial membrane protein that is related to the mitochondrial Oxa1p and the Alb3 protein of chloroplasts. These proteins are required in the membrane integration process of newly synthesized proteins that do not require the classical Sec machinery. Here we demonstrate that YidC is sufficient for the membrane integration of a Sec-independent protein. Microgram amounts of the purified single-spanning Pf3 coat protein were efficiently inserted into proteoliposomes containing the purified YidC. A mutant Pf3 coat protein with an extended hydrophobic region was inserted independently of YidC into the membrane both in vivo and in vitro, but its insertion was accelerated by YidC. These results show that YidC can function separately from the Sec translocase to integrate membrane proteins into the lipid bilayer.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adenosine Triphosphatases / metabolism
  • Bacterial Proteins / metabolism
  • Capsid Proteins / chemistry
  • Capsid Proteins / metabolism
  • Escherichia coli Proteins / physiology*
  • Liposomes / metabolism
  • Membrane Transport Proteins / metabolism
  • Membrane Transport Proteins / physiology*
  • Proteolipids / metabolism
  • SEC Translocation Channels
  • SecA Proteins


  • Bacterial Proteins
  • Capsid Proteins
  • Escherichia coli Proteins
  • Liposomes
  • Membrane Transport Proteins
  • Proteolipids
  • SEC Translocation Channels
  • YIDC protein, E coli
  • proteoliposomes
  • major coat protein, Pseudomonas phage Pf3
  • Adenosine Triphosphatases
  • SecA Proteins