extracellular domain (ECD) found in activin receptor type-2A (ACTR-IIA) and similar proteins
ACTR-IIA (EC 2.7.11.30, also called activin receptor type IIA) 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. ACTR-IIA is the receptor for activin A, activin B, and inhibin A. It mediates induction of adipogenesis by GDF6. ACTR-IIA also interacts with type I receptor ACVR1 and bone morphogenetic protein 7 (BMP7). This model corresponds to the extracellular domain (ECD) of ACTR-IIA, 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.",