title: Characterization of the annular lipid shell of the Sec translocon.
abstract: The bacterial Sec translocase in its minimal form consists of a membrane-embedded protein-conducting pore SecYEG that interacts with the motor protein SecA to mediate the translocation of secretory proteins. In addition, the SecYEG translocon interacts with the accessory SecDFyajC membrane complex and the membrane protein insertase YidC. To examine the composition of the native lipid environment in the vicinity of the SecYEG complex and its impact on translocation activity, styrene-maleic acid lipid particles (SMALPs) were used to extract SecYEG with its lipid environment directly from native Escherichia coli membranes without the use of detergents. This allowed the co-extraction of SecYEG in complex with SecA, but not with SecDFyajC or YidC. Lipid analysis of the SecYEG-SMALPs revealed an enrichment of negatively charged lipids in the vicinity of SecYEG, which in detergent assisted reconstitution of the Sec translocase are crucial for the translocation activity. Such lipid enrichment was not found with separately extracted SecDFyajC or YidC, which demonstrates a specific interaction between SecYEG and negatively charged lipids.
authors.affiliation: Department of Molecular Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute, Nijenborgh 7, 9727 AG Groningen, The Netherlands; Zernike Institute for Advanced Materials, Nijenborgh 7, 9727 AG Groningen, The Netherlands.
authors.forename: Irfan
authors.initials: I
authors.lastname: Prabudiansyah
authors.affiliation: Department of Molecular Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute, Nijenborgh 7, 9727 AG Groningen, The Netherlands; Zernike Institute for Advanced Materials, Nijenborgh 7, 9727 AG Groningen, The Netherlands.
authors.forename: Ilja
authors.initials: I
authors.lastname: Kusters
authors.affiliation: Department of Molecular Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute, Nijenborgh 7, 9727 AG Groningen, The Netherlands; Zernike Institute for Advanced Materials, Nijenborgh 7, 9727 AG Groningen, The Netherlands.
authors.forename: Antonella
authors.initials: A
authors.lastname: Caforio
authors.affiliation: Department of Molecular Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute, Nijenborgh 7, 9727 AG Groningen, The Netherlands; Zernike Institute for Advanced Materials, Nijenborgh 7, 9727 AG Groningen, The Netherlands. Electronic address: a.j.m.driessen@rug.nl.
authors.forename: Arnold J M
authors.initials: AJ
authors.lastname: Driessen
mesh_terms: D000251:Adenosine Triphosphatases / Q000737:chemistry* / Q000648:ultrastructure; D001426:Bacterial Proteins / Q000737:chemistry* / Q000648:ultrastructure; D004789:Enzyme Activation; D004926:Escherichia coli / Q000201:enzymology*; D029968:Escherichia coli Proteins / Q000737:chemistry*; D008051:Lipid Bilayers / Q000737:chemistry*; D008298:Maleates / Q000737:chemistry; D026901:Membrane Transport Proteins / Q000737:chemistry* / Q000648:ultrastructure; D011510:Proteolipids / Q000737:chemistry*; D000069816:SEC Translocation Channels; D000081416:SecA Proteins; D055672:Static Electricity; D020058:Styrene / Q000737:chemistry
chemical_list: D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D008051:Lipid Bilayers; D008298:Maleates; D026901:Membrane Transport Proteins; D011510:Proteolipids; D000069816:SEC Translocation Channels; C020485:proteoliposomes; D020058:Styrene; C030272:maleic acid; D000251:Adenosine Triphosphatases; D000081416:SecA Proteins
keywords: Lipid–protein interaction; SMALP; Sec translocon; Styrene-maleic acid; Translocation