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SecDFyajC forms a heterotetrameric complex with YidC
Author(s) -
Nouwen Nico,
Driessen Arnold J. M.
Publication year - 2002
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1046/j.1365-2958.2002.02972.x
Subject(s) - translocase , heterotrimeric g protein , biology , microbiology and biotechnology , membrane protein , transport protein , protein subunit , biochemistry , membrane , g protein , chromosomal translocation , signal transduction , gene
Summary The Escherichia coli preprotein translocase is composed of a ‘preprotein conducting channel’ domain that consists of the peripherally bound translocation ATPase SecA and the heterotrimeric SecYEG membrane protein complex. SecD, SecF, and YajC form another heterotrimeric complex that can associate with the SecYEG complex. YidC is an essential membrane protein that plays a role in the integration of newly synthesized membrane proteins, and has been shown to co‐purify with SecYEG when all translocase components are overproduced. Here, we demonstrate that under conditions that YidC co‐purifies with overproduced SecDFyajC it does not co‐purify with overproduced SecYEG. Moreover, this interaction of YidC with the SecDFyajC complex is also found at chromosomal protein levels of SecD, SecF and YajC. Closer examination of the SecDFyajC–YidC complex showed that YidC binds to SecD and SecF, whereas YajC interacts only with SecF. As SecF and YajC have previously been shown to interact with SecY, we propose that these two proteins link the heterotetrameric SecDFyajC–YidC complex to the SecYEG complex.