PDBsum entry 1jba

Lyase

PDB id: 1jba

Contents

Protein chain

189 a.a. *

Metals

_CA ×3

* Residue conservation analysis

PDB id:

1jba

Name:

Lyase

Title:

Unmyristoylated gcap-2 with three calcium ions bound

Structure:

Protein (guanylate cyclase activating protein 2). Chain: a. Synonym: gcap-2. Engineered: yes

Source:

Bos taurus. Cattle. Organism_taxid: 9913. Tissue: retina. Cell: rod. Cellular_location: cytoplasm. Expressed in: escherichia coli bl21. Expression_system_taxid: 511693. Expression_system_cell_line: bl21(de3).

NMR struc:

22 models

Authors:

J.B.Ames,A.M.Dizhoor,M.Ikura,K.Palczewski,L.Stryer

Key ref:

J.B.Ames et al. (1999). Three-dimensional structure of guanylyl cyclase activating protein-2, a calcium-sensitive modulator of photoreceptor guanylyl cyclases. J Biol Chem, 274, 19329-19337. PubMed id: 10383444 DOI: 10.1074/jbc.274.27.19329

Date:

03-Apr-99 Release date: 10-Dec-99

Protein chain

P51177  (GUC1B_BOVIN) -  Guanylyl cyclase-activating protein 2 from Bos taurus

Seq: 204 a.a.

Struc: 189 a.a.

Enzyme reactions

• Enzyme class: E.C.4.6.1.2 - guanylate cyclase.
• Reaction: GTP = 3',5'-cyclic GMP + diphosphate

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

reference

DOI no: 10.1074/jbc.274.27.19329

J Biol Chem 274:19329-19337 (1999)

PubMed id: 10383444

Three-dimensional structure of guanylyl cyclase activating protein-2, a calcium-sensitive modulator of photoreceptor guanylyl cyclases.

J.B.Ames, A.M.Dizhoor, M.Ikura, K.Palczewski, L.Stryer.

ABSTRACT

Guanylyl cyclase activating protein-2 (GCAP-2) is a Ca2+-sensitive regulator of phototransduction in retinal photoreceptor cells. GCAP-2 activates retinal guanylyl cyclases at low Ca2+ concentration (<100 nM) and inhibits them at high Ca2+ (>500 nM). The light-induced lowering of the Ca2+ level from approximately 500 nM in the dark to approximately 50 nM following illumination is known to play a key role in visual recovery and adaptation. We report here the three-dimensional structure of unmyristoylated GCAP-2 with three bound Ca2+ ions as determined by nuclear magnetic resonance spectroscopy of recombinant, isotopically labeled protein. GCAP-2 contains four EF-hand motifs arranged in a compact tandem array like that seen previously in recoverin. The root mean square deviation of the main chain atoms in the EF-hand regions is 2.2 A in comparing the Ca2+-bound structures of GCAP-2 and recoverin. EF-1, as in recoverin, does not bind calcium because it contains a disabling Cys-Pro sequence. GCAP-2 differs from recoverin in that the calcium ion binds to EF-4 in addition to EF-2 and EF-3. A prominent exposed patch of hydrophobic residues formed by EF-1 and EF-2 (Leu24, Trp27, Phe31, Phe45, Phe48, Phe49, Tyr81, Val82, Leu85, and Leu89) may serve as a target-binding site for the transmission of calcium signals to guanylyl cyclase.

Selected figure(s)

Figure 5.
Fig. 5. Schematic ribbon representation (A) and space-filling model (B) of the energy-minimized average structure of unmyristoylated GCAP-2 with three Ca^2+ bound. The side chain atoms of residues at the domain interface (Ala^63, Ala^67, Ile^103, and Ile^120) are shown in A and the color scheme is as in Fig. 4. The figure was generated using Molscript (49) and Raster3d (23).

Figure 8.
Fig. 8. Space-filling representation (A) and ball-and-stick model (B) of side chain atoms of the exposed hydrophobic patch of GCAP-2. Hydrophobic, negatively charged, and positively charged residues are highlighted in yellow, red, and blue, respectively. Solvent-exposed hydrophobic residues from EF-1 and EF-2 are indicated.

The above figures are reprinted by permission from the ASBMB: J Biol Chem (1999, 274, 19329-19337) copyright 1999.

Figures were selected by an automated process.