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1la3

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(New page: 200px<br /><applet load="1la3" size="450" color="white" frame="true" align="right" spinBox="true" caption="1la3" /> '''Solution structure of recoverin mutant, E85Q...)
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[[Image:1la3.gif|left|200px]]<br /><applet load="1la3" size="450" color="white" frame="true" align="right" spinBox="true"
 
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caption="1la3" />
 
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'''Solution structure of recoverin mutant, E85Q'''<br />
 
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==Overview==
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==Solution structure of recoverin mutant, E85Q==
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Recoverin, a member of the EF-hand superfamily, serves as a calcium sensor, in retinal rod cells. A myristoyl or related fatty acyl group covalently, attached to the N-terminus of recoverin facilitates the binding of, recoverin to retinal disk membranes by a mechanism known as the, Ca2+-myristoyl switch. Previous structural studies revealed that the, myristoyl group of recoverin is sequestered inside the protein core in the, absence of calcium. The cooperative binding of two calcium ions to the, second and third EF-hands (EF-2 and EF-3) of recoverin leads to the, extrusion of the fatty acid. Here we present nuclear magnetic resonance, (NMR), fluorescence, and calcium-binding studies of a myristoylated, recoverin mutant (myr-E85Q) designed to abolish high-affinity calcium, binding to EF-2 and thereby trap the myristoylated protein with calcium, bound solely to EF-3. Equilibrium calcium-binding studies confirm that, only one Ca2+ binds to myr-E85Q under the conditions of this study with a, dissociation constant of 100 microM. Fluorescence and NMR spectra of the, Ca2+-free myr-E85Q are identical to those of Ca2+-free wild type, indicating that the E85Q mutation does not alter the stability and, structure of the Ca2+-free protein. In contrast, the fluorescence and NMR, spectra of half-saturated myr-E85Q (one bound Ca2+) look different from, those of Ca2+-saturated wild type (two bound Ca2+), suggesting that, half-saturated myr-E85Q may represent a structural intermediate. We report, here the three-dimensional structure of Ca2+-bound myr-E85Q as determined, by NMR spectroscopy. The N-terminal myristoyl group of Ca2+-bound myr-E85Q, is sequestered within a hydrophobic cavity lined by many aromatic residues, (F23, W31, Y53, F56, F83, and Y86) resembling that of Ca2+-free recoverin., The structure of Ca2+-bound myr-E85Q in the N-terminal region (residues, 2-90) is similar to that of Ca2+-free recoverin, whereas the C-terminal, region (residues 100-202) is more similar to that of Ca2+-bound wild type., Hence, the structure of Ca2+-bound myr-E85Q represents a hybrid between, the structures of recoverin with zero and two Ca2+ bound. The binding of, Ca2+ to EF-3 leads to local structural changes within the EF-hand that, alter the domain interface and cause a 45 degrees swiveling of the N- and, C-terminal domains, resulting in a partial unclamping of the myristoyl, group. We propose that Ca2+-bound myr-E85Q may represent a stable, intermediate state in the kinetic mechanism of the calcium-myristoyl, switch.
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<StructureSection load='1la3' size='340' side='right'caption='[[1la3]]' scene=''>
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== Structural highlights ==
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<table><tr><td colspan='2'>[[1la3]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Bos_taurus Bos taurus]. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1LA3 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1LA3 FirstGlance]. <br>
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</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Solution NMR</td></tr>
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<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=MYR:MYRISTIC+ACID'>MYR</scene></td></tr>
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<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1la3 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1la3 OCA], [https://pdbe.org/1la3 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1la3 RCSB], [https://www.ebi.ac.uk/pdbsum/1la3 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1la3 ProSAT]</span></td></tr>
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</table>
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== Function ==
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[https://www.uniprot.org/uniprot/RECO_BOVIN RECO_BOVIN] Seems to be implicated in the pathway from retinal rod guanylate cyclase to rhodopsin. May be involved in the inhibition of the phosphorylation of rhodopsin in a calcium-dependent manner. The calcium-bound recoverin prolongs the photoresponse.<ref>PMID:8097896</ref> <ref>PMID:8392055</ref>
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== Evolutionary Conservation ==
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[[Image:Consurf_key_small.gif|200px|right]]
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Check<jmol>
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<jmolCheckbox>
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<scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/la/1la3_consurf.spt"</scriptWhenChecked>
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<scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
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<text>to colour the structure by Evolutionary Conservation</text>
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</jmolCheckbox>
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</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=1la3 ConSurf].
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<div style="clear:both"></div>
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==About this Structure==
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==See Also==
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1LA3 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bos_taurus Bos taurus] with CA and MYR as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1LA3 OCA].
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*[[Recoverin%2C a calcium-activated myristoyl switch|Recoverin%2C a calcium-activated myristoyl switch]]
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== References ==
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==Reference==
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<references/>
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Structure and calcium-binding studies of a recoverin mutant (E85Q) in an allosteric intermediate state., Ames JB, Hamasaki N, Molchanova T, Biochemistry. 2002 May 7;41(18):5776-87. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=11980481 11980481]
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__TOC__
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</StructureSection>
[[Category: Bos taurus]]
[[Category: Bos taurus]]
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[[Category: Single protein]]
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[[Category: Large Structures]]
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[[Category: Ames, J.B.]]
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[[Category: Ames JB]]
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[[Category: Hamasaki, N.]]
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[[Category: Hamasaki N]]
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[[Category: Molchanova, T.]]
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[[Category: Molchanova T]]
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[[Category: CA]]
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[[Category: MYR]]
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[[Category: calcium]]
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[[Category: e85q]]
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[[Category: ef-hand]]
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[[Category: vision]]
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''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Tue Nov 20 20:25:13 2007''
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Current revision

Solution structure of recoverin mutant, E85Q

PDB ID 1la3

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