Structure of reduced DsbA from Escherichia coli in solution

Schirra, HJ, Renner, C, Czisch, M, Huber-Wunderlich, M, Holak, TA and Glockshuber, R (1998) Structure of reduced DsbA from Escherichia coli in solution. Biochemistry, 37 18: 6263-6276. doi:10.1021/bi980136y


Author Schirra, HJ
Renner, C
Czisch, M
Huber-Wunderlich, M
Holak, TA
Glockshuber, R
Title Structure of reduced DsbA from Escherichia coli in solution
Journal name Biochemistry   Check publisher's open access policy
ISSN 0006-2960
Publication date 1998-05-01
Year available 1998
Sub-type Article (original research)
DOI 10.1021/bi980136y
Open Access Status DOI
Volume 37
Issue 18
Start page 6263
End page 6276
Total pages 14
Place of publication WASHINGTON
Publisher AMER CHEMICAL SOC
Language eng
Abstract The three-dimensional structure of reduced DsbA from Escherichia coli in aqueous solution has been determined by nuclear magnetic resonance (NMR) spectroscopy and is compared with the crystal structure of oxidized DsbA [Guddat, L. W., Bardwell, J. C. A., Zander, T., and Martin, J. L. (1997) Protein Sci. 6, 1148-1156]. DsbA is a monomeric 21 kDa protein which consists of 189 residues and is required for disulfide bond formation in the periplasm of E. coli. On the basis of sequence-specific H-1 NMR assignments, 1664 nuclear Overhauser enhancement distance constraints, 118 hydrogen bond distance constraints, and 293 dihedral angle constraints were obtained as the input for the structure calculations by simulated annealing with the program X-PLOR. The enzyme is made up of two domains. The catalytic domain has a thioredoxin-like fold with a five-stranded beta-sheet and three alpha-helices, and the second domain consists of four alpha-helices and is inserted into the thioredoxin motif. The active site between Cys30 and Cys33 is located at the N terminus of the first alpha-helix in the thioredoxin-like domain. The solution structure of reduced DsbA is rather similar to the crystal structure of the oxidized enzyme but exhibits a different relative orientation of both domains. In addition, the conformations of the active site and a loop between strand beta 5 and helix alpha 7 are slightly different. These structural differences may reflect important functional requirements in the reaction cycle of DsbA as they appear to facilitate the release of oxidized polypeptides from reduced DsbA. The extremely low pK(a) value of the nucleophilic active site thiol of Cys30 in reduced DsbA is most likely caused by its interactions with the dipole of the active site helix and the side chain of His32, as no other charged residues are located next to the sulfur atom of Cys30 in the solution structure.
Keyword Disulfide Bond Formation
Nuclear-Magnetic-Resonance
Active-Site Cysteine
Formation In-Vivo
Sequential Backbone Assignment
Pancreatic Trypsin-Inhibitor
Thioredoxin-Like Domain
3-Dimensional Structure
Formation Invivo
Distance Geometry
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status Unknown

Document type: Journal Article
Sub-type: Article (original research)
Collection: ResearcherID Downloads - Archived
 
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