2k0r

Publication Abstract from PubMed

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.

Solution Structure and Backbone Dynamics of the Cysteine 103 to Serine Mutant of the N-Terminal Domain of DsbD from Neisseria meningitides.,Quinternet M, Tsan P, Selme L, Beaufils C, Jacob C, Boschi-Muller S, Averlant-Petit MC, Branlant G, Cung MT Biochemistry. 2008 Nov 5. PMID:18983169^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.