1rl3
Crystal structure of cAMP-free R1a subunit of PKACrystal structure of cAMP-free R1a subunit of PKA
Structural highlights
FunctionKAP0_BOVIN Regulatory subunit of the cAMP-dependent protein kinases involved in cAMP signaling in cells. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedIn eukaryotes the primary target for cAMP, a ubiquitous second messenger, is cAMP-dependent protein kinase (PKA). Understanding how binding and release of cAMP changes the cAMP binding domains and then triggers long-range allosteric responses is an important challenge. This conformational switching requires structure solutions of cAMP binding domains in cAMP-bound and cAMP-free states. We describe for the first time a crystal structure of the cAMP binding domains of PKA type Ialpha regulatory subunit where site A is occupied by cGMP and site B is unoccupied. The structure reveals that the carboxyl terminus of domain B serves as a hydrophobic cap, locking the cyclic nucleotide via its adenine ring into the beta-barrel. In the absence of cAMP, the "cap" is released via an extension of the C-terminal helix. This simple hinge mechanism for binding and release of cAMP also provides a mechanism for allosteric communication between sites A and B. RIalpha subunit of PKA: a cAMP-free structure reveals a hydrophobic capping mechanism for docking cAMP into site B.,Wu J, Brown S, Xuong NH, Taylor SS Structure. 2004 Jun;12(6):1057-65. PMID:15274925[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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