1U3A

mutant DsbA

Summary for 1U3A

• Entry DOI: 10.2210/pdb1u3a/pdb
• Related: 1TI1
• Descriptor: Thiol: disulfide interchange protein dsbA, 3,6,9,12,15,18,21,24-OCTAOXAHEXACOSAN-1-OL (3 entities in total)
• Functional Keywords: thiol oxidoreductase, thiol disulfide interchange, thioredoxin, oxidoreductase
• Biological source: Escherichia coli
• Cellular location: Periplasm: P24991
• Total number of polymer chains: 4
• Total formula weight: 85288.81

Authors

Serre, L. (deposition date: 2004-07-21, release date: 2005-05-03, Last modification date: 2024-11-13)

Primary citation

Ondo-Mbele, E.,Vives, C.,Kone, A.,Serre, L.
Intriguing conformation changes associated with the trans/cis isomerization of a prolyl residue in the active site of the DsbA C33A mutant
J.Mol.Biol., 347:555-563, 2005

PubMed Abstract: Escherichia coli DsbA belongs to the thioredoxin family and catalyzes the formation of disulfide bonds during the folding of proteins in the bacterial periplasm. It active site (C30-P31-H32-C33) consists of a disulfide bridge that is transferred to newly translocated proteins. The work reported here refers to the DsbA mutant termed C33A that retains, towards reduced unfolded thrombin inhibitor, an activity comparable with the wild-type enzyme. Besides, C33A is also able to form a stable covalent complex with DsbB, the membrane protein responsible for maintaining DsbA in its active form. We have determined the crystal structure of C33A at 2.0 angstroms resolution. Although the general architecture of wt DsbA is conserved, we observe the trans/cis isomerization of P31 in the active site and further conformational changes in the so-called "peptide binding groove" region. Interestingly, these modifications involve residues that are specific to DsbA but not to the thioredoxin family fold. The C33A crystal structure exhibits as well a hydrophobic ligand bound close to the active site of the enzyme. The structural analysis of C33A may actually explain the peculiar behavior of this mutant in regards with its interaction with DsbB and thus provides new insights for understanding the catalytic cycle of DsbA.

PubMed: 15755450
DOI: 10.1016/j.jmb.2005.01.049

Experimental method

X-RAY DIFFRACTION (2 Å)