InterPro domain: IPR036356

ERp29 (also known as ERp28 and ERp31) is a ubiquitously expressed endoplasmic reticulum protein found in mammals [ 1 ]. This protein has an N-terminal thioredoxin-like domain, which is homologous to the domain of human protein disulphide isomerase (PDI). ERp29 may help mediate the chaperone function of PDI. The C-terminal Erp29 domain has a 5-helical bundle fold. ERp29 is thought to form part of the thyroglobulin folding complex [ 2 ].

The Drosophila homologue, Wind, is the product of windbeutel, an essential gene in the development of dorsal-ventral patterning. Wind is required for correct targeting of Pipe, a Golgi-resident type II transmembrane protein with homology to 2-O-sulfotransferase. The C-terminal domain of Wind is thought to provide a distinct site required for interaction with its substrate, Pipe [ 3 ].

1. Thioredoxin fold as homodimerization module in the putative chaperone ERp29: NMR structures of the domains and experimental model of the 51 kDa dimer. Structure 9, 457-71
2. Identification of ERp29, an endoplasmic reticulum lumenal protein, as a new member of the thyroglobulin folding complex. J. Biol. Chem. 277, 17009-15
3. Crystal structure and functional analysis of Drosophila Wind, a protein-disulfide isomerase-related protein. J. Biol. Chem. 278, 44600-7