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2hwn
From Proteopedia
Crystal Structure of RII alpha Dimerization/Docking domain of PKA bound to the D-AKAP2 peptide
Overview
A kinase-anchoring proteins (AKAPs) target PKA to specific microdomains by using an amphipathic helix that docks to N-terminal dimerization and docking (D/D) domains of PKA regulatory (R) subunits. To understand specificity, we solved the crystal structure of the helical motif from D-AKAP2, a dual-specific AKAP, bound to the RIIalpha D/D domain. The 1.6 Angstrom structure reveals how this dynamic, hydrophobic docking site is assembled. A stable, hydrophobic docking groove is formed by the helical interface of two RIIalpha protomers. The flexible N terminus of one protomer is then recruited to the site, anchored to the peptide through two essential isoleucines. The other N terminus is disordered. This asymmetry provides greater possibilities for AKAP docking. Although there is strong discrimination against RIalpha in the N terminus of the AKAP helix, the hydrophobic groove discriminates against RIIalpha. RIalpha, with a cavity in the groove, can accept a bulky tryptophan, whereas RIIalpha requires valine.
About this Structure
2HWN is a Single protein structure of sequence from Rattus norvegicus. Full crystallographic information is available from OCA.
Reference
A dynamic mechanism for AKAP binding to RII isoforms of cAMP-dependent protein kinase., Kinderman FS, Kim C, von Daake S, Ma Y, Pham BQ, Spraggon G, Xuong NH, Jennings PA, Taylor SS, Mol Cell. 2006 Nov 3;24(3):397-408. PMID:17081990 Page seeded by OCA on Sun May 4 06:48:10 2008
