title: Structural basis and kinetics of DsbD-dependent cytochrome c maturation.
abstract: DsbD from Escherichia coli transports two electrons from cytoplasmic thioredoxin to the periplasmic substrate proteins DsbC, DsbG and CcmG. DsbD consists of an N-terminal periplasmic domain (nDsbD), a C-terminal periplasmic domain, and a central transmembrane domain. Each domain possesses two cysteines required for electron transport. Herein, we demonstrate fast (3.9 x 10(5) M(-1)s(-1)) and direct disulfide exchange between nDsbD and CcmG, a highly specific disulfide reductase essential for cytochrome c maturation. We determined the crystal structure of the disulfide-linked complex between nDsbD and the soluble part of CcmG at 1.94 A resolution. In contrast to the other two known complexes of nDsbD with target proteins, the N-terminal segment of nDsbD contributes to specific recognition of CcmG. This and other features, like the possibility of using an additional interaction surface, constitute the structural basis for the adaptability of nDsbD to different protein substrates.
authors: Biochemisches Institut, Universität Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland.
authors: Christian U
authors: CU
authors: Stirnimann
authors: Anna
authors: A
authors: Rozhkova
authors: Ulla
authors: U
authors: Grauschopf
authors: Markus G
authors: MG
authors: Grütter
authors: Rudi
authors: R
authors: Glockshuber
authors: Guido
authors: G
authors: Capitani
mesh_terms: D001665:Binding Sites; D002851:Chromatography, High Pressure Liquid; D018360:Crystallography, X-Ray; D045304:Cytochromes c / Q000737:chemistry*; D003593:Cytoplasm / Q000378:metabolism; D019281:Dimerization; D004220:Disulfides / Q000737:chemistry; D004579:Electron Transport; D004583:Electrons; D004926:Escherichia coli / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000737:chemistry / Q000502:physiology*; D007700:Kinetics; D008565:Membrane Proteins / Q000737:chemistry / Q000502:physiology*; D008954:Models, Biological; D008958:Models, Molecular; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000737:chemistry; D010100:Oxygen / Q000737:chemistry; D010957:Plasmids / Q000378:metabolism; D011487:Protein Conformation; D011490:Protein Disulfide Reductase (Glutathione) / Q000737:chemistry; D017434:Protein Structure, Tertiary; D013879:Thioredoxins / Q000737:chemistry; D013997:Time Factors
chemical_list: D004220:Disulfides; D029968:Escherichia coli Proteins; D008565:Membrane Proteins; D013879:Thioredoxins; D045304:Cytochromes c; D010088:Oxidoreductases; C094848:DsbD electron transport protein, E coli; C485980:Ccmg protein, E coli; D011490:Protein Disulfide Reductase (Glutathione); D010100:Oxygen