Sec-dependent membrane protein insertion: sequential interaction of nascent FtsQ with SecY and YidC.

ABSTRACT: Recent studies identified YidC as a novel membrane factor that may play a key role in membrane insertion of inner membrane proteins (IMPs), both in conjunction with the Sec-translocase and as a separate entity. Here, we show that the type II IMP FtsQ requires both the translocase and, to a lesser extent, YidC in vivo. Using photo-crosslinking we demonstrate that the transmembrane (TM) domain of the nascent IMP FtsQ inserts into the membrane close to SecY and lipids, and moves to a combined YidC/lipid environment upon elongation. These data are consistent with a crucial role for YidC in the lateral transfer of TM domains from the Sec translocase into the lipid bilayer.

SUBMITTER: Urbanus ML 

PROVIDER: S-EPMC1083902 | biostudies-literature | 2001 Jun

REPOSITORIES: biostudies-literature