1u7e
From Proteopedia
The crystal structure of a Protein Kinase A complex
Overview
The 2.0-angstrom structure of the cyclic adenosine monophosphate (cAMP)-dependent protein kinase (PKA) catalytic subunit bound to a deletion mutant of a regulatory subunit (RIalpha) defines a previously unidentified extended interface. The complex provides a molecular mechanism for inhibition of PKA and suggests how cAMP binding leads to activation. The interface defines the large lobe of the catalytic subunit as a stable scaffold where Tyr247 in the G helix and Trp196 in the phosphorylated activation loop serve as anchor points for binding RIalpha. These residues compete with cAMP for the phosphate binding cassette in RIalpha. In contrast to the catalytic subunit, RIalpha undergoes major conformational changes when the complex is compared with cAMP-bound RIalpha. The inhibitor sequence docks to the active site, whereas the linker, also disordered in free RIalpha, folds across the extended interface. The beta barrel of cAMP binding domain A, which is the docking site for cAMP, remains largely intact in the complex, whereas the helical subdomain undergoes major reorganization.
About this Structure
1U7E is a Protein complex structure of sequences from Bos taurus and Mus musculus. Full crystallographic information is available from OCA.
Reference
Crystal structure of a complex between the catalytic and regulatory (RIalpha) subunits of PKA., Kim C, Xuong NH, Taylor SS, Science. 2005 Feb 4;307(5710):690-6. PMID:15692043 Page seeded by OCA on Sat May 3 10:50:54 2008
