title: Crystallographic structure of SurA, a molecular chaperone that facilitates folding of outer membrane porins.
abstract: The SurA protein facilitates correct folding of outer membrane proteins in gram-negative bacteria. The sequence of Escherichia coli SurA presents four segments, two of which are peptidyl-prolyl isomerases (PPIases); the crystal structure reveals an asymmetric dumbbell, in which the amino-terminal, carboxy-terminal, and first PPIase segments of the sequence form a core structural module, and the second PPIase segment is a satellite domain tethered approximately 30 A from this module. The core module, which is implicated in membrane protein folding, has a novel fold that includes an extended crevice. Crystal contacts show that peptides bind within the crevice, suggesting a model for chaperone activity whereby segments of polypeptide may be repetitively sequestered and released during the membrane protein-folding process.
authors.affiliation: Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305, USA.
authors.forename: Eduard
authors.initials: E
authors.lastname: Bitto
authors.forename: David B
authors.initials: DB
authors.lastname: McKay
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D002352:Carrier Proteins; D002462:Cell Membrane / Q000378:metabolism*; D018360:Crystallography, X-Ray; D004583:Electrons; D004926:Escherichia coli / Q000201:enzymology; D029968:Escherichia coli Proteins; D008958:Models, Molecular; D018832:Molecular Chaperones / Q000737:chemistry*; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry; D019696:Peptidylprolyl Isomerase / Q000737:chemistry*; D018272:Porins / Q000737:chemistry*; D011485:Protein Binding; D011487:Protein Conformation; D017510:Protein Folding; D017434:Protein Structure, Tertiary; D017386:Sequence Homology, Amino Acid
chemical_list: D002352:Carrier Proteins; D029968:Escherichia coli Proteins; D018832:Molecular Chaperones; D010455:Peptides; D018272:Porins; C490900:SurA protein, E coli; C098640:periplasmic peptidylprolyl cis-trans isomerase; D019696:Peptidylprolyl Isomerase