title: SecDFyajC forms a heterotetrameric complex with YidC.
abstract: 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.
authors.affiliation: Department of Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9751 NN Haren, The Netherlands. n.nouwen@biol.rug.nl
authors.forename: Nico
authors.initials: N
authors.lastname: Nouwen
authors.forename: Arnold J M
authors.initials: AJ
authors.lastname: Driessen
mesh_terms: D000942:Antigens, Bacterial; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins; D046911:Macromolecular Substances; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D026901:Membrane Transport Proteins; D008954:Models, Biological; D010957:Plasmids / Q000235:genetics / Q000378:metabolism; D021122:Protein Subunits; D021381:Protein Transport / Q000502:physiology; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D046911:Macromolecular Substances; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D021122:Protein Subunits; D011993:Recombinant Fusion Proteins; C499394:SecD protein, E coli; C489583:SecF protein, E coli; C412443:YIDC protein, E coli; C116101:YajC protein, Brucella; C075767:secD protein, Bacteria; C075768:secF protein, Bacteria