1myj: Difference between revisions

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New page: left|200px<br /><applet load="1myj" size="450" color="white" frame="true" align="right" spinBox="true" caption="1myj, resolution 1.9Å" /> '''DISTAL POLARITY IN LI...
 
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[[Image:1myj.gif|left|200px]]<br /><applet load="1myj" size="450" color="white" frame="true" align="right" spinBox="true"
caption="1myj, resolution 1.9&Aring;" />
'''DISTAL POLARITY IN LIGAND BINDING TO MYOGLOBIN: STRUCTURAL AND FUNCTIONAL CHARACTERIZATION OF A THREONINE68(E11) MUTANT'''<br />


==Overview==
==DISTAL POLARITY IN LIGAND BINDING TO MYOGLOBIN: STRUCTURAL AND FUNCTIONAL CHARACTERIZATION OF A THREONINE68(E11) MUTANT==
Site-directed mutagenesis studies have confirmed that the distal histidine, in myoglobin stabilizes bound O2 by hydrogen bonding and have suggested, that it is the polar character of the imidazole side chain rather than its, size that limits the rate of ligand entry into the protein. We constructed, an isosteric Val68 to Thr replacement in pig myoglobin (i) to investigate, whether the O2 affinity could be increased by the introduction of a second, hydrogen-bonding group into the distal heme pocket and (ii) to examine the, influence of polarity on the ligand binding rates more rigorously. The, 1.9-A crystal structure of Thr68 aquometmyoglobin confirms that the mutant, and wild-type proteins are essentially isostructural and reveals that the, beta-OH group of Thr68 is in a position to form hydrogen-bonding, interactions both with the coordinated water molecule and with the main, chain greater than C=O of residue 64. The rate of azide binding to the, ferric form of the Thr68 mutant was 60-fold lower than that for the, wild-type protein, consistent with the proposed stabilization of the, coordinated water molecule. However, bound O2 is destabilized in the, ferrous form of the mutant protein. The observed 17-fold lowering of the, O2 affinity may be a consequence of the hydrogen-bonding interaction made, between the Thr68 beta-OH group and the carbonyl oxygen of residue 64., Overall association rate constants for O2, NO, and alkyl isocyanide, binding to ferrous pig myoglobin were 3-10-fold lower for the mutant, compared to the wild-type protein, whereas that for CO binding was little, affected.(ABSTRACT TRUNCATED AT 250 WORDS)
<StructureSection load='1myj' size='340' side='right'caption='[[1myj]], [[Resolution|resolution]] 1.90&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1myj]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Sus_scrofa Sus scrofa]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1MYJ OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1MYJ FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.9&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1myj FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1myj OCA], [https://pdbe.org/1myj PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1myj RCSB], [https://www.ebi.ac.uk/pdbsum/1myj PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1myj ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/MYG_PIG MYG_PIG] Serves as a reserve supply of oxygen and facilitates the movement of oxygen within muscles.
== Evolutionary Conservation ==
[[Image:Consurf_key_small.gif|200px|right]]
Check<jmol>
  <jmolCheckbox>
    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/my/1myj_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
    <text>to colour the structure by Evolutionary Conservation</text>
  </jmolCheckbox>
</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=1myj ConSurf].
<div style="clear:both"></div>


==About this Structure==
==See Also==
1MYJ is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Sus_scrofa Sus scrofa] with SO4 and HEM as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1MYJ OCA].
*[[Myoglobin 3D structures|Myoglobin 3D structures]]
 
__TOC__
==Reference==
</StructureSection>
Distal pocket polarity in ligand binding to myoglobin: structural and functional characterization of a threonine68(E11) mutant., Smerdon SJ, Dodson GG, Wilkinson AJ, Gibson QH, Blackmore RS, Biochemistry. 1991 Jun 25;30(25):6252-60. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=1905570 1905570]
[[Category: Large Structures]]
[[Category: Single protein]]
[[Category: Sus scrofa]]
[[Category: Sus scrofa]]
[[Category: Dauter, Z.]]
[[Category: Dauter Z]]
[[Category: Oldfield, T.J.]]
[[Category: Oldfield TJ]]
[[Category: Petratos, K.]]
[[Category: Petratos K]]
[[Category: Smerdon, S.J.]]
[[Category: Smerdon SJ]]
[[Category: Wilkinson, A.J.]]
[[Category: Wilkinson AJ]]
[[Category: Wilson, K.S.]]
[[Category: Wilson KS]]
[[Category: HEM]]
[[Category: SO4]]
[[Category: oxygen storage]]
 
''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Tue Nov 20 21:48:44 2007''

Latest revision as of 10:50, 14 February 2024

DISTAL POLARITY IN LIGAND BINDING TO MYOGLOBIN: STRUCTURAL AND FUNCTIONAL CHARACTERIZATION OF A THREONINE68(E11) MUTANTDISTAL POLARITY IN LIGAND BINDING TO MYOGLOBIN: STRUCTURAL AND FUNCTIONAL CHARACTERIZATION OF A THREONINE68(E11) MUTANT

Structural highlights

1myj is a 2 chain structure with sequence from Sus scrofa. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:X-ray diffraction, Resolution 1.9Å
Ligands:,
Resources:FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

MYG_PIG Serves as a reserve supply of oxygen and facilitates the movement of oxygen within muscles.

Evolutionary Conservation

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

See Also

1myj, resolution 1.90Å

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