The domain within your query sequence starts at position 27 and ends at position 134; the E-value for the Thioredoxin domain shown below is 4.9e-37.



PFAM accession number:PF00085
Interpro abstract (IPR013766):

Thioredoxins [ (PUBMED:3896121) (PUBMED:2668278) (PUBMED:7788289) (PUBMED:7788290) ] are small disulphide-containing redox proteins that have been found in all the kingdoms of living organisms. Thioredoxin serves as a general protein disulphide oxidoreductase. It interacts with a broad range of proteins by a redox mechanism based on reversible oxidation of two cysteine thiol groups to a disulphide, accompanied by the transfer of two electrons and two protons. The net result is the covalent interconversion of a disulphide and a dithiol. In the NADPH-dependent protein disulphide reduction, thioredoxin reductase (TR) catalyses the reduction of oxidised thioredoxin (trx) by NADPH using FAD and its redox-active disulphide; reduced thioredoxin then directly reduces the disulphide in the substrate protein [ (PUBMED:3896121) ].

Thioredoxin is present in prokaryotes and eukaryotes and the sequence around the redox-active disulphide bond is well conserved. All thioredoxins contain a cis-proline located in a loop preceding beta-strand 4, which makes contact with the active site cysteines, and is important for stability and function [ (PUBMED:8590004) ]. Thioredoxin belongs to a structural family that includes glutaredoxin, glutathione peroxidase, bacterial protein disulphide isomerase DsbA, and the N-terminal domain of glutathione transferase [ (PUBMED:7788290) ]. Thioredoxins have a beta-alpha unit preceding the motif common to all these proteins.

A number of eukaryotic proteins contain domains evolutionary related to thioredoxin, most of them are protein disulphide isomerases (PDI). PDI ( EC ) [ (PUBMED:3371540) (PUBMED:2537773) (PUBMED:7940678) ] is an endoplasmic reticulum multi-functional enzyme that catalyses the formation and rearrangement of disulphide bonds during protein folding [ (PUBMED:7913469) ]. All PDI contains two or three (ERp72) copies of the thioredoxin domain, each of which contributes to disulphide isomerase activity, but which are functionally non-equivalent [ (PUBMED:7983029) ]. Moreover, PDI exhibits chaperone-like activity towards proteins that contain no disulphide bonds, i.e. behaving independently of its disulphide isomerase activity [ (PUBMED:7635143) ]. The various forms of PDI which are currently known are:

  • PDI major isozyme; a multifunctional protein that also function as the beta subunit of prolyl 4-hydroxylase ( EC ), as a component of oligosaccharyl transferase ( EC ), as thyroxine deiodinase ( EC ), as glutathione-insulin transhydrogenase ( EC ) and as a thyroid hormone-binding protein
  • ERp60 (ER-60; 58 Kd microsomal protein). ERp60 was originally thought to be a phosphoinositide-specific phospholipase C isozyme and later to be a protease.
  • ERp72.
  • ERp5.

Bacterial proteins that act as thiol:disulphide interchange proteins that allows disulphide bond formation in some periplasmic proteins also contain a thioredoxin domain. These proteins include:

  • Escherichia coli DsbA (or PrfA) and its orthologs in Vibrio cholerae (TtcpG) and Haemophilus influenzae (Por).
  • E. coli DsbC (or XpRA) and its orthologues in Erwinia chrysanthemi and H. influenzae.
  • E. coli DsbD (or DipZ) and its H. influenzae orthologue.
  • E. coli DsbE (or CcmG) and orthologues in H. influenzae.
  • Rhodobacter capsulatus (Rhodopseudomonas capsulata) (HelX), Rhiziobiacae (CycY and TlpA).

This entry represents the thioredoxin domain.

This is a PFAM domain. For full annotation and more information, please see the PFAM entry Thioredoxin