title: In vivo cross-linking of the SecA and SecY subunits of the Escherichia coli preprotein translocase.
abstract: Precursor protein translocation across the Escherichia coli inner membrane is mediated by the translocase, which is composed of a heterotrimeric integral membrane protein complex with SecY, SecE, and SecG as subunits and peripherally bound SecA. Cross-linking experiments were conducted to study which proteins are associated with SecA in vivo. Formaldehyde treatment of intact cells results in the specific cross-linking of SecA to SecY. Concurrently with the increased membrane association of SecA, an elevated amount of cross-linked product was obtained in cells harboring overproduced SecYEG complex. Cross-linked SecA copurified with hexahistidine-tagged SecY and not with SecE. The data indicate that SecA and SecY coexist as a stable complex in the cytoplasmic membrane in vivo.
authors.affiliation: Department of Microbiology, University of Groningen, Haren, The Netherlands.
authors.forename: E H
authors.initials: EH
authors.lastname: Manting
authors.forename: C
authors.initials: C
authors.lastname: van der Does
authors.forename: A J
authors.initials: AJ
authors.lastname: Driessen
mesh_terms: D000251:Adenosine Triphosphatases / Q000737:chemistry* / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism; D001692:Biological Transport; D002462:Cell Membrane / Q000378:metabolism; D003432:Cross-Linking Reagents; D004926:Escherichia coli / Q000737:chemistry / Q000201:enzymology* / Q000378:metabolism; D029968:Escherichia coli Proteins; D026901:Membrane Transport Proteins; D008970:Molecular Weight; D011994:Recombinant Proteins; D000069816:SEC Translocation Channels; D000081416:SecA Proteins
chemical_list: D001426:Bacterial Proteins; D003432:Cross-Linking Reagents; D029968:Escherichia coli Proteins; D026901:Membrane Transport Proteins; D011994:Recombinant Proteins; D000069816:SEC Translocation Channels; C057841:SecY protein, E coli; D000255:Adenosine Triphosphate; D000251:Adenosine Triphosphatases; D000081416:SecA Proteins