title: Solution NMR studies of membrane-protein-chaperone complexes.
abstract: The biosynthesis of the bacterial outer membrane depends on molecular chaperones that protect hydrophobic membrane proteins against aggregation while transporting them across the periplasm. In our ongoing research, we use high-resolution NMR spectroscopy in aqueous solution as the main  technique to characterize the structures and biological functions of these membrane-protein-chaperone complexes. Here, we describe NMR studies addressing three functional aspects of periplasmic membrane-protein-chaperone complexes. Firstly, the Escherichia coli outer membrane  protein OmpX binds to each of the two chaperones, Skp and SurA, in structurally at least partially similar states despite fundamental differences between the three-dimensional structures of the chaperones. Secondly, we show that the Skp-bound state of OmpX is equivalent to a chemically denatured  state in terms of its refolding competence into detergent micelles in vitro. Thirdly, we use amino acid mutation analysis to show that the interaction of OmpX to Skp is not dominated by the two most hydrophobic segments of OmpX.
authors.affiliation: University of Basel Biozentrum Klingelbergstr. 70 CH-4056 Basel, Switzerland.
authors.forename: Björn M
authors.initials: BM
authors.lastname: Burmann
authors.forename: Sebastian
authors.initials: S
authors.lastname: Hiller
mesh_terms: D001425:Bacterial Outer Membrane Proteins / Q000378:metabolism; D002352:Carrier Proteins / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism; D004926:Escherichia coli / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000378:metabolism; D006867:Hydrolases / Q000378:metabolism; D008565:Membrane Proteins / Q000737:chemistry* / Q000378:metabolism*; D008958:Models, Molecular; D018832:Molecular Chaperones / Q000737:chemistry* / Q000378:metabolism*; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D019696:Peptidylprolyl Isomerase / Q000378:metabolism; D017510:Protein Folding
chemical_list: D001425:Bacterial Outer Membrane Proteins; D002352:Carrier Proteins; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; D008565:Membrane Proteins; D018832:Molecular Chaperones; C072721:Skp protein, E coli; C482905:OmpX protein, E coli; D006867:Hydrolases; C490900:SurA protein, E coli; D019696:Peptidylprolyl Isomerase