2H9R: Docking and dimerization domain (D/D) of the regulatory subunit of the Type II-alpha cAMP-dependent protein kinase A associated with a Peptide derived from an A-kinase anchoring protein (AKAP)

The specificity of intracellular signaling events is controlled, in part, by compartmentalization of protein kinases and phosphatases. The subcellular localization of these enzymes is often maintained by protein- protein interactions. A prototypic example is the compartmentalization of the cAMP-dependent protein kinase (PKA) through its association with A-kinase anchoring proteins (AKAPs). A docking and dimerization domain (D/D) located within the first 45 residues of each regulatory (R) subunit protomer forms a high affinity binding site for its anchoring partner. We now report the structures of two D/D-AKAP peptide complexes obtained by solution NMR methods, one with Ht31(493-515) and the other with AKAP79(392-413). We present the first direct structural data demonstrating the helical nature of the peptides. The structures reveal conserved hydrophobic interaction surfaces on the helical AKAP peptides and the PKA R subunit, which are responsible for mediating the high affinity association in the complexes. In a departure from the dimer-dimer interactions seen in other X-type four-helix bundle dimeric proteins, our structures reveal a novel hydrophobic groove that accommodates one AKAP per RIIalpha D/D.
PDB ID: 2H9RDownload
MMDB ID: 41011
PDB Deposition Date: 2006/6/10
Updated in MMDB: 2007/10
Experimental Method:
solution nmr
Source Organism:
Rattus norvegicus
Similar Structures:
Molecular Components in 2H9R
Label Count Molecule
Proteins (3 molecules)
Camp-dependent Protein Kinase Type Ii-alpha Regulatory Subunit(Gene symbol: Prkar2a)
Molecule annotation
22-mer From A-kinase Anchor Protein 5(Gene symbol: AKAP5)
Molecule annotation
* Click molecule labels to explore molecular sequence information.

Citing MMDB