Download MendeleyA Dynamic Mechanism for AKAP Binding to RII Isoforms of cAMP-Dependent Protein Kinase.
Kinderman, F.S., Kim, C., von Daake, S., Ma, Y., Pham, B.Q., Spraggon, G., Xuong, N.H., Jennings, P.A., Taylor, S.S.(2006) Mol Cell 24: 397-408
- PubMed: 17081990
- DOI: https://doi.org/10.1016/j.molcel.2006.09.015
- Primary Citation of Related Structures:
2HWN - PubMed Abstract:
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.
Organizational Affiliation:
Department of Chemistry and Biochemistry, University of California, San Diego, San Diego, California 92093, USA.
