extracellular domain (ECD) found in bone morphogenetic protein receptor type-1A (BMPR-1A) and similar proteins
BMPR-1A (EC 2.7.11.30, also called BMP type-1A receptor, or activin receptor-like kinase 3 (ALK-3), or serine/threonine-protein kinase receptor R5 (SKR5), or CD292) on ligand binding, forms a receptor complex consisting of two type II, and two type I transmembrane serine/threonine kinases. Type II receptors phosphorylate and activate type I receptors which autophosphorylate, then bind and activate SMAD transcriptional regulators. BMPR-1A is the receptor for BMP2, BMP4, GDF5, and GDF6. It positively regulates chondrocyte differentiation through GDF5 interaction and mediates induction of adipogenesis by GDF6. This model corresponds to extracellular domain (ECD) of BMPR-1A, which belongs to Ly-6 antigen/uPA receptor-like (LU) superfamily and exhibits a snake toxin-like fold (also known as three-finger toxin/3FTx fold or three-fingered protein/TFP domain fold).
Jiyao W et al.(2023). "The conserved domain database in 2023.",