Solution structure and backbone dynamics of the cysteine 103 to serine mutant of the N-terminal domain of DsbD from Neisseria meningitidis.
The DsbD protein is essential for electron transfer from the cytoplasm to the periplasm of Gram-negative bacteria. Its N-terminal domain dispatches electrons coming from cytoplasmic thioredoxin (Trx), via its central transmembrane and C-terminal domains, to its periplasmic partners: DsbC, DsbE/CcmG, and DsbG. Previous structural studies described the latter proteins as Trx-like folds possessing a characteristic C-X-X-C motif able to generate a disulfide bond upon oxidation. The Escherichia coli nDsbD displays an immunoglobulin-like fold in which two cysteine residues (Cys103 and Cys109) allow a disulfide bond exchange with its biological partners.We have determined the structure in solution and the backbone dynamics of the C103S mutant of the N-terminal domain of DsbD from Neisseria meningitidis. Our results highlight significant structural changes concerning the beta-sheets and the local topology of the active site compared with the oxidized form of the E. coli nDsbD. The structure reveals a "cap loop" covering the active site, similar to the oxidized E. coli nDsbD X-ray structure. However, regions featuring enhanced mobility were observed both near to and distant from the active site, revealing a capacity of structural adjustments in the active site and in putative interaction areas with nDsbD biological partners. Results are discussed in terms of functional consequences.
Quinternet
Marc
M
Laboratoire de Chimie Physique Macromoleculaire, UMR 7568 CNRS-INPL, Nancy Universite, 1 rue Grandville, B.P. 20451, 54001 Nancy cedex, France.
Tsan
Pascale
P
Selme
Laure
L
Beaufils
Chrystel
C
Jacob
Christophe
C
Boschi-Muller
Sandrine
S
Averlant-Petit
Marie-Christine
MC
Branlant
Guy
G
Cung
Manh-Thong
MT
D020134:Catalytic Domain; D003545:Cysteine / Q000235:genetics*; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D050505:Mutant Proteins / Q000737:chemistry* / Q000235:genetics; D009154:Mutation / Q000235:genetics*; D009345:Neisseria meningitidis / Q000201:enzymology*; D010088:Oxidoreductases / Q000737:chemistry* / Q000235:genetics*; D017434:Protein Structure, Tertiary / Q000235:genetics; D012694:Serine / Q000235:genetics*; D012996:Solutions
D050505:Mutant Proteins; D012996:Solutions; D012694:Serine; D010088:Oxidoreductases; D003545:Cysteine