1u3a | pdb_00001u3a
mutant DsbA
Structural highlights
FunctionDSBA_ECOLI Required for disulfide bond formation in some periplasmic proteins such as PhoA or OmpA. Acts by transferring its disulfide bond to other proteins and is reduced in the process. DsbA is reoxidized by DsbB. Required for pilus biogenesis. PhoP-regulated transcription is redox-sensitive, being activated when the periplasm becomes more reducing (deletion of dsbA/dsbB, treatment with dithiothreitol). MgrB acts between DsbA/DsbB and PhoP/PhoQ in this pathway.[1] [2] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedEscherichia 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. Intriguing conformation changes associated with the trans/cis isomerization of a prolyl residue in the active site of the DsbA C33A mutant.,Ondo-Mbele E, Vives C, Kone A, Serre L J Mol Biol. 2005 Apr 1;347(3):555-63. PMID:15755450[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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