1ias
From Proteopedia
CYTOPLASMIC DOMAIN OF UNPHOSPHORYLATED TYPE I TGF-BETA RECEPTOR CRYSTALLIZED WITHOUT FKBP12
Overview
The type I TGF beta receptor (T beta R-I) is activated by phosphorylation of the GS region, a conserved juxtamembrane segment located just N-terminal to the kinase domain. We have studied the molecular mechanism of receptor activation using a homogeneously tetraphosphorylated form of T beta R-I, prepared using protein semisynthesis. Phosphorylation of the GS region dramatically enhances the specificity of T beta R-I for the critical C-terminal serines of Smad2. In addition, tetraphosphorylated T beta R-I is bound specifically by Smad2 in a phosphorylation-dependent manner and is no longer recognized by the inhibitory protein FKBP12. Thus, phosphorylation activates T beta R-I by switching the GS region from a binding site for an inhibitor into a binding surface for substrate. Our observations suggest that phosphoserine/phosphothreonine-dependent localization is a key feature of the T beta R-I/Smad activation process.
About this Structure
1IAS is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.
Reference
The TGF beta receptor activation process: an inhibitor- to substrate-binding switch., Huse M, Muir TW, Xu L, Chen YG, Kuriyan J, Massague J, Mol Cell. 2001 Sep;8(3):671-82. PMID:11583628 Page seeded by OCA on Fri May 2 19:46:53 2008
