Domain

DSBA-like thioredoxin domain (IPR001853)

Short name: DSBA-like_thioredoxin_dom

Overlapping homologous superfamilies

Domain relationships

None.

Description

DSBA is a sub-family of the Thioredoxin family [PMID: 9149147]. The efficient and correct folding of bacterial disulphide bonded proteins in vivo is dependent upon a class of periplasmic oxidoreductase proteins called DsbA, after the Escherichia coli enzyme. The bacterial protein-folding factor DsbA is the most oxidizing of the thioredoxin family. DsbA catalyses disulphide-bond formation during the folding of secreted proteins. The extremely oxidizing nature of DsbA has been proposed to result from either domain motion or stabilising active-site interactions in the reduced form. DsbA's highly oxidizing nature is a result of hydrogen bond, electrostatic and helix-dipole interactions that favour the thiolate over the disulphide at the active site [PMID: 9655827]. In the pathogenic bacterium Vibrio cholerae, the DsbA homologue (TcpG) is responsible for the folding, maturation and secretion of virulence factors.

While the overall architecture of TcpG and DsbA is similar and the surface features are retained in TcpG, there are significant differences. For example, the kinked active site helix results from a three-residue loop in DsbA, but is caused by a proline in TcpG (making TcpG more similar to thioredoxin in this respect). Furthermore, the proposed peptide binding groove of TcpG is substantially shortened compared with that of DsbA due to a six-residue deletion. Also, the hydrophobic pocket of TcpG is more shallow and the acidic patch is much less extensive than that of E. coli DsbA [PMID: 9149147].

GO terms

Biological Process

No terms assigned in this category.

Molecular Function

GO:0015035 protein disulfide oxidoreductase activity

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.
Pfam