1hrm: Difference between revisions
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[[Image: | ==THE PROXIMAL LIGAND VARIANT HIS93TYR OF HORSE HEART MYOGLOBIN== | ||
<StructureSection load='1hrm' size='340' side='right' caption='[[1hrm]], [[Resolution|resolution]] 1.70Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[1hrm]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Equus_caballus Equus caballus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1HRM OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1HRM FirstGlance]. <br> | |||
</td></tr><tr><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene><br> | |||
<tr><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1hrm FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1hrm OCA], [http://www.rcsb.org/pdb/explore.do?structureId=1hrm RCSB], [http://www.ebi.ac.uk/pdbsum/1hrm PDBsum]</span></td></tr> | |||
<table> | |||
== 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/hr/1hrm_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/chain_selection.php?pdb_ID=2ata ConSurf]. | |||
<div style="clear:both"></div> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
The spectroscopic and structural properties of the His93Tyr variant of horse heart myoglobin have been studied to assess the effects of replacing the proximal His residue of this protein with a tyrosyl residue as occurs in catalases from various sources. The variant in the ferric form exhibits electronic spectra that are independent of pH between pH 7 and 10, and it exhibits changes in absorption maxima and intensity that are consistent with a five-coordinate heme iron center at the active site. The EPR spectrum of the variant is that of a high-spin, rhombic system similar to that reported for bovine liver catalase. The 1D 1H-NMR spectrum of the variant confirms the five-coordinate nature of the heme iron center and exhibits a broad resonance at 112.5 ppm that is attributable to the meta protons of the phenolate ligand. This result indicates that the new Tyr ligand flips at a significant rate in this protein. The thermal stability of the Fe(III) derivative is unchanged from that of the wild-type protein (pH 8) while the midpoint reduction potential [-208 mV vs SHE (pH 8.0, 25 degrees C)] is about 250 mV lower. The three-dimensional structure of the variant determined by X-ray diffraction analysis confirms the five-coordinate nature of the heme iron center and establishes that the introduction of a proximal Tyr ligand is accommodated by a shift of the F helix (residues 88-99) in which this residue resides away from the heme pocket. Additional effects of this change are small shifts in the positions of Leu29, a heme propionate, and a heme vinyl group that are accompanied by altered hydrogen bonding interactions with the heme prosthetic group.(ABSTRACT TRUNCATED AT 250 WORDS) | |||
The proximal ligand variant His93Tyr of horse heart myoglobin.,Hildebrand DP, Burk DL, Maurus R, Ferrer JC, Brayer GD, Mauk AG Biochemistry. 1995 Feb 14;34(6):1997-2005. PMID:7849057<ref>PMID:7849057</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
==See Also== | ==See Also== | ||
*[[Myoglobin|Myoglobin]] | *[[Myoglobin|Myoglobin]] | ||
== References == | |||
== | <references/> | ||
< | __TOC__ | ||
</StructureSection> | |||
[[Category: Equus caballus]] | [[Category: Equus caballus]] | ||
[[Category: Brayer, G D.]] | [[Category: Brayer, G D.]] | ||
[[Category: Burk, D L.]] | [[Category: Burk, D L.]] | ||
[[Category: Oxygen transport]] | [[Category: Oxygen transport]] | ||
