The domain within your query sequence starts at position 30 and ends at position 139; the E-value for the Thioredoxin domain shown below is 1.1e-23.



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:

This entry represents the thioredoxin domain.

GO process:cell redox homeostasis (GO:0045454)

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