1UN2

Crystal structure of circularly permuted CPDSBA_Q100T99: Preserved Global Fold and Local Structural Adjustments

Replaces:  1DYV

Summary for 1UN2

• Entry DOI: 10.2210/pdb1un2/pdb
• Related: 1A23 1A24 1A2J 1A2L 1A2M 1AC1 1ACV 1BQ7 1DSB 1FVJ 1FVK
• Descriptor: THIOL-DISULFIDE INTERCHANGE PROTEIN (2 entities in total)
• Functional Keywords: disulfide oxidoreductase, oxidoreductase, protein disulfide isomerase, protein folding, thioredoxin, redox protein, disulfide bond formation, circular permutation
• Biological source: ESCHERICHIA COLI
• Total number of polymer chains: 1
• Total formula weight: 21839.83

Authors

Manjasetty, B.A.,Hennecke, J.,Glockshuber, R.,Heinemann, U. (deposition date: 2003-09-03, release date: 2003-09-26, Last modification date: 2023-12-13)

Primary citation

Manjasetty, B.A.,Hennecke, J.,Glockshuber, R.,Heinemann, U.
Structure of Circularly Permuted Dsba(Q100T99): Preserved Global Fold and Local Structural Adjustments
Acta Crystallogr.,Sect.D, 60:304-, 2004

PubMed Abstract: The thiol-disulfide oxidoreductase DsbA is required for efficient formation of disulfide bonds in the Escherichia coli periplasm. The enzyme is the strongest oxidant of the family of thioredoxin-like proteins and three-dimensional structures of both oxidized and reduced forms are known. DsbA consists of a catalytic thioredoxin-like domain and a helical domain that is inserted into the thioredoxin motif. Here, the X-ray structure of a circularly permuted variant, cpDsbA(Q100T99), is reported in which the natural termini are joined by the pentapeptide linker GGGTG, leading to a continuous thioredoxin domain, and new termini that have been introduced in the helical domain by breaking the peptide bond Thr99-Gln100. cpDsbA(Q100T99) is catalytically active in vivo and in vitro. The crystal structure of oxidized cpDsbA(Q100T99), determined by molecular replacement at 2.4 A resolution, was found to be very similar to that of wild-type DsbA. The lower thermodynamic stability of cpDsbA(Q100T99) relative to DsbA is associated with small structural changes within the molecule, especially near the new termini and the circularizing linker. The active-site helices and adjacent loops display increased flexibility compared with oxidized DsbA.

PubMed: 14747707
DOI: 10.1107/S0907444903028695

Experimental method

X-RAY DIFFRACTION (2.4 Å)