MIR domain, beta-trefoil fold, found in family of metazoan stromal cell-derived factor 2 (SDF-2)
The metazoan SDF-2 family includes SDF-2 and SDF2-like protein 1 (SDF2L1). SDF-2 is a secretory protein involved in multiple endoplasmic reticulum (ER) functions, including the misfolded protein catabolic process, protein glycosylation, and ER protein quality control. SDF2L1, also called PWP1-interacting protein 8, is an endoplasmic reticulum (ER)-localized protein that plays a role in ER-associated degradation (ERAD) of misfolded proinsulin in pancreatic beta-cells. It is a component of the endoplasmic reticulum (ER) chaperone complex and interacts with alpha- and beta-defensins. SDF2L1 may also act as a tumor suppressor that play an important role in a variety of cancers, such as breast cancer and ovarian cancer. Members in this family contain a MIR (protein mannosyltransferase, IP3R and RyR) domain with beta-trefoil fold, which is characterized by 12 beta strands folded into three similar trefoil subdomains (alpha, beta, and gamma) associated to give an overall structure with pseudo-3-fold symmetry.