Solution structure and backbone dynamics of the cysteine 103 to serine mutant of the N-terminal domain of DsbD from Neisseria meningitidis.
Fiche publication
Date publication
décembre 2008
Auteurs
Membres identifiés du Cancéropôle Est :
Pr BOSCHI-MULLER Sandrine, Dr JACOB Christophe
Tous les auteurs :
Quinternet M, Tsan P, Selme L, Beaufils C, Jacob C, Boschi-Muller S, Averlant-Petit MC, Branlant G, Cung MT
Lien Pubmed
Résumé
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.
Référence
Biochemistry. 2008 Dec 2;47(48):12710-20.