FGF domain, beta-trefoil fold, found in fibroblast growth factor 7 (FGF7) and similar proteins
FGF7, also called heparin-binding growth factor 7 (HBGF7), or keratinocyte growth factor (KGF), plays an important role in the regulation of embryonic development, cell proliferation, and cell differentiation. It is required for normal branching morphogenesis. It is a growth factor active on keratinocytes. It may act as major paracrine effector of normal epithelial cell proliferation. FGF7 interacts with fibroblast growth factor receptor FGFR2 and fibroblast growth factor-binding protein 1 (FGFBP1). Affinity between fibroblast growth factors (FGFs) and their receptors is increased by heparan sulfate glycosaminoglycans that function as coreceptors. FGF7 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.