1irc

<StructureSection load='1irc' size='340' side='right' caption='[[1irc]], [[Resolution|resolution]] 2.17&Aring;' scene=''>

<table><tr><td colspan='2'>[[1irc]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Phycd Phycd]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1IRC OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1IRC FirstGlance]. <br>

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene>, <scene name='pdbligand=IMD:IMIDAZOLE'>IMD</scene></td></tr>

<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">SPERM WHALE MYOGLOBIN SYNTHETI ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=9755 PHYCD])</td></tr>

<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1irc FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1irc OCA], [http://pdbe.org/1irc PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1irc RCSB], [http://www.ebi.ac.uk/pdbsum/1irc PDBsum]</span></td></tr>

[[http://www.uniprot.org/uniprot/MYG_PHYMC MYG_PHYMC]] Serves as a reserve supply of oxygen and facilitates the movement of oxygen within muscles.

<scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/ir/1irc_consurf.spt"</scriptWhenChecked>

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== Publication Abstract from PubMed ==

The proximal bond between the iron atom of the heme group and the N epsilon of histidine F8 in myoglobin (Mb) and hemoglobin (Hb) is presumed to be an important determinant of heme binding, protein structure, and oxygen binding. Here a system is described in which the proximal ligand is provided intermolecularly by the histidine side chain mimic imidazole. The proximal ligand of sperm whale Mb is replaced with glycine (H93G) using site-directed mutagenesis. The addition of imidazole to Escherichia coli expressing this gene reconstitutes myoglobin function. H93G Mb purified in the presence of imidazole is spectroscopically similar to wild-type Mb in combination with a wide variety of distal ligands. The crystal structure of H93G Mb, determined in the presence of imidazole, reveals that an imidazole molecule is bonded to the heme iron on the proximal side, substituting in trans for the side-chain function of the proximal histidine of wild-type Mb. Although H93G Mb is similar in spectroscopic and gross structural detail to wild-type Mb, subtle differences exist in the orientation of imidazole with respect to the heme group. trans-Complementation of proximal ligand function will allow the proximal bond in hemoproteins to be chemically substituted beyond the limits of the genetic code.

Replacement of the proximal ligand of sperm whale myoglobin with free imidazole in the mutant His-93--&gt;Gly.,Barrick D Biochemistry. 1994 May 31;33(21):6546-54. PMID:8204590<ref>PMID:8204590</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>

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<div class="pdbe-citations 1irc" style="background-color:#fffaf0;"></div>

*[[Myoglobin|Myoglobin]]

[[Category: Phycd]]

[[Category: Barrick, D E]]

[[Category: Feese, M]]

[[Category: Heme]]

[[Category: Respiratory protein]]