2i94
NMR Structure of recoverin bound to rhodopsin kinaseNMR Structure of recoverin bound to rhodopsin kinase
Structural highlights
FunctionGRK1_BOVIN Retina-specific kinase involved in the signal turnoff via phosphorylation of rhodopsin (RHO), the G protein- coupled receptor that initiates the phototransduction cascade (PubMed:12686556, PubMed:16675451, PubMed:21299498). This rapid desensitization is essential for scotopic vision and permits rapid adaptation to changes in illumination (By similarity). May play a role in the maintenance of the outer nuclear layer in the retina (By similarity).[UniProtKB:Q9WVL4][1] [2] [3] 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 PubMedRecoverin, a member of the neuronal calcium sensor branch of the EF-hand superfamily, serves as a calcium sensor that regulates rhodopsin kinase (RK) activity in retinal rod cells. We report here the NMR structure of Ca(2+)-bound recoverin bound to a functional N-terminal fragment of rhodopsin kinase (residues 1-25, called RK25). The overall main-chain structure of recoverin in the complex is similar to structures of Ca(2+)-bound recoverin in the absence of target (<1.8A root-mean-square deviation). The first eight residues of recoverin at the N terminus are solvent-exposed, enabling the N-terminal myristoyl group to interact with target membranes, and Ca(2+) is bound at the second and third EF-hands of the protein. RK25 in the complex forms an amphipathic helix (residues 4-16). The hydrophobic face of the RK25 helix (Val-9, Val-10, Ala-11, Ala-14, and Phe-15) interacts with an exposed hydrophobic groove on the surface of recoverin lined by side-chain atoms of Trp-31, Phe-35, Phe-49, Ile-52, Tyr-53, Phe-56, Phe-57, Tyr-86, and Leu-90. Residues of recoverin that contact RK25 are highly conserved, suggesting a similar target binding site structure in all neuronal calcium sensor proteins. Site-specific mutagenesis and deletion analysis confirm that the hydrophobic residues at the interface are necessary and sufficient for binding. The recoverin-RK25 complex exhibits Ca(2+)-induced binding to rhodopsin immobilized on concanavalin-A resin. We propose that Ca(2+)-bound recoverin is bound between rhodopsin and RK in a ternary complex on rod outer segment disk membranes, thereby blocking RK interaction with rhodopsin at high Ca(2+). Structural basis for calcium-induced inhibition of rhodopsin kinase by recoverin.,Ames JB, Levay K, Wingard JN, Lusin JD, Slepak VZ J Biol Chem. 2006 Dec 1;281(48):37237-45. Epub 2006 Oct 4. PMID:17020884[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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