PDBsum entry 2i94

Protein binding

PDB id: 2i94

Contents

Protein chains

182 a.a. *

16 a.a. *

Metals

_CA ×2

* Residue conservation analysis

PDB id:

2i94

Name:

Protein binding

Title:

Nmr structure of recoverin bound to rhodopsin kinase

Structure:

Recoverin. Chain: a. Synonym: p26. Engineered: yes. Rhodopsin kinase. Chain: b. Fragment: rk25. Synonym: rk, g protein-coupled receptor kinase 1. Engineered: yes

Source:

Bos taurus. Cattle. Organism_taxid: 9913. Expressed in: escherichia coli bl21(de3). Expression_system_taxid: 469008.

NMR struc:

10 models

Authors:

J.B.Ames

Key ref:

J.B.Ames et al. (2006). Structural basis for calcium-induced inhibition of rhodopsin kinase by recoverin. J Biol Chem, 281, 37237-37245. PubMed id: 17020884 DOI: 10.1074/jbc.M606913200

Date:

05-Sep-06 Release date: 10-Oct-06

Protein chain

P21457  (RECO_BOVIN) -  Recoverin from Bos taurus

Seq: 202 a.a.

Struc: 182 a.a.

Protein chain

P28327  (RK_BOVIN) -  Rhodopsin kinase GRK1 from Bos taurus

Seq: 561 a.a.

Struc: 16 a.a.

Enzyme reactions

• Enzyme class: Chain B: E.C.2.7.11.14 - rhodopsin kinase.
• Reaction:
  1. L-seryl-[rhodopsin] + ATP = O-phospho-L-seryl-[rhodopsin] + ADP + H⁺
  2. L-threonyl-[rhodopsin] + ATP = O-phospho-L-threonyl-[rhodopsin] + ADP + H⁺

Molecule diagrams generated from .mol files obtained from the KEGG ftp site

reference

DOI no: 10.1074/jbc.M606913200

J Biol Chem 281:37237-37245 (2006)

PubMed id: 17020884

Structural basis for calcium-induced inhibition of rhodopsin kinase by recoverin.

J.B.Ames, K.Levay, J.N.Wingard, J.D.Lusin, V.Z.Slepak.

ABSTRACT

Recoverin, 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+).

Selected figure(s)

Figure 5.
FIGURE 5. Intermolecular interactions between recoverin and RK25. Side-chain atoms in the hydrophobic groove of recoverin (yellow) interact with side-chain atoms from the hydrophobic surface of RK25 helix (magenta).

Figure 7.
FIGURE 7. Schematic model of Ca^2+-induced inhibition of rhodopsin kinase. Myristoylation (red) targets Ca^2+-bound recoverin to the membrane surface, where it interacts with rhodopsin. Recoverin also interacts with the N-terminal helix of rhodopsin kinase (magenta), forming a ternary complex on the membrane surface that blocks phosphorylation of rhodopsin. Light activation leads to a lowering of cytosolic Ca^2+, causing conformational changes in recoverin that sequester the covalently attached myristoyl group and disrupt the interaction with rhodopsin kinase. Ca^2+-free recoverin then dissociates from the membrane surface, allowing RK to phosphorylate the C-terminal tail of light-excited rhodopsin.

The above figures are reprinted by permission from the ASBMB: J Biol Chem (2006, 281, 37237-37245) copyright 2006.

Figures were selected by an automated process.