FGF domain, beta-trefoil fold, found in fibroblast growth factor 4 (FGF4) and similar proteins
FGF4, also called heparin secretory-transforming protein 1 (HST-1), or HSTF-1, or heparin-binding growth factor 4 (HBGF4), or transforming protein KS3, plays an important role in the regulation of embryonic development, cell proliferation, and cell differentiation. It is required for normal limb and cardiac valve development during embryogenesis. It interacts with fibroblast growth factor receptors, FGFR1, FGFR2, FGFR3, and FGFR4. Affinity between fibroblast growth factors (FGFs) and their receptors is increased by heparan sulfate glycosaminoglycans that function as coreceptors. FGF4 contains a FGF 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.
Jiyao W et al.(2023). "The conserved domain database in 2023.",