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[[Image: | ==X-ray structure of the metcyano form of dehaloperoxidase from amphitrite ornata: evidence for photoreductive lysis of iron-cyanide bond== | ||
<StructureSection load='3kun' size='340' side='right' caption='[[3kun]], [[Resolution|resolution]] 1.26Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[3kun]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Amphitrite_ornata Amphitrite ornata]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3KUN OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=3KUN FirstGlance]. <br> | |||
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=CYN:CYANIDE+ION'>CYN</scene>, <scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene></td></tr> | |||
<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[3kuo|3kuo]]</td></tr> | |||
<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">DHPA ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=129555 Amphitrite ornata])</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=3kun FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3kun OCA], [http://www.rcsb.org/pdb/explore.do?structureId=3kun RCSB], [http://www.ebi.ac.uk/pdbsum/3kun 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/ku/3kun_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 == | |||
X-ray crystal structures of the metcyano form of dehaloperoxidase-hemoglobin (DHP A) from Amphitrite ornata (DHPCN) and the C73S mutant of DHP A (C73SCN) were determined using synchrotron radiation in order to further investigate the geometry of diatomic ligands coordinated to the heme iron. The DHPCN structure was also determined using a rotating-anode source. The structures show evidence of photoreduction of the iron accompanied by dissociation of bound cyanide ion (CN(-)) that depend on the intensity of the X-ray radiation and the exposure time. The electron density is consistent with diatomic molecules located in two sites in the distal pocket of DHPCN. However, the identities of the diatomic ligands at these two sites are not uniquely determined by the electron-density map. Consequently, density functional theory calculations were conducted in order to determine whether the bond lengths, angles and dissociation energies are consistent with bound CN(-) or O(2) in the iron-bound site. In addition, molecular-dynamics simulations were carried out in order to determine whether the dynamics are consistent with trapped CN(-) or O(2) in the second site of the distal pocket. Based on these calculations and comparison with a previously determined X-ray crystal structure of the C73S-O(2) form of DHP [de Serrano et al. (2007), Acta Cryst. D63, 1094-1101], it is concluded that CN(-) is gradually replaced by O(2) as crystalline DHP is photoreduced at 100 K. The ease of photoreduction of DHP A is consistent with the reduction potential, but suggests an alternative activation mechanism for DHP A compared with other peroxidases, which typically have reduction potentials that are 0.5 V more negative. The lability of CN(-) at 100 K suggests that the distal pocket of DHP A has greater flexibility than most other hemoglobins. | |||
X-ray structure of the metcyano form of dehaloperoxidase from Amphitrite ornata: evidence for photoreductive dissociation of the iron-cyanide bond.,de Serrano VS, Davis MF, Gaff JF, Zhang Q, Chen Z, D'Antonio EL, Bowden EF, Rose R, Franzen S Acta Crystallogr D Biol Crystallogr. 2010 Jul;66(Pt 7):770-82. Epub 2010 Jun 19. PMID:20606257<ref>PMID:20606257</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
==See Also== | ==See Also== | ||
*[[Dehaloperoxidase|Dehaloperoxidase]] | *[[Dehaloperoxidase|Dehaloperoxidase]] | ||
== References == | |||
== | <references/> | ||
< | __TOC__ | ||
</StructureSection> | |||
[[Category: Amphitrite ornata]] | [[Category: Amphitrite ornata]] | ||
[[Category: Chen, Z | [[Category: Chen, Z]] | ||
[[Category: Franzen, S | [[Category: Franzen, S]] | ||
[[Category: Gaff, J F | [[Category: Gaff, J F]] | ||
[[Category: Rose, R | [[Category: Rose, R]] | ||
[[Category: Serrano, V S | [[Category: Serrano, V S]] | ||
[[Category: Crystal structure of metcyano form of dehaloperoxydase]] | [[Category: Crystal structure of metcyano form of dehaloperoxydase]] | ||
[[Category: Heme]] | [[Category: Heme]] | ||
Revision as of 11:59, 9 December 2014
X-ray structure of the metcyano form of dehaloperoxidase from amphitrite ornata: evidence for photoreductive lysis of iron-cyanide bondX-ray structure of the metcyano form of dehaloperoxidase from amphitrite ornata: evidence for photoreductive lysis of iron-cyanide bond
Structural highlights
Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedX-ray crystal structures of the metcyano form of dehaloperoxidase-hemoglobin (DHP A) from Amphitrite ornata (DHPCN) and the C73S mutant of DHP A (C73SCN) were determined using synchrotron radiation in order to further investigate the geometry of diatomic ligands coordinated to the heme iron. The DHPCN structure was also determined using a rotating-anode source. The structures show evidence of photoreduction of the iron accompanied by dissociation of bound cyanide ion (CN(-)) that depend on the intensity of the X-ray radiation and the exposure time. The electron density is consistent with diatomic molecules located in two sites in the distal pocket of DHPCN. However, the identities of the diatomic ligands at these two sites are not uniquely determined by the electron-density map. Consequently, density functional theory calculations were conducted in order to determine whether the bond lengths, angles and dissociation energies are consistent with bound CN(-) or O(2) in the iron-bound site. In addition, molecular-dynamics simulations were carried out in order to determine whether the dynamics are consistent with trapped CN(-) or O(2) in the second site of the distal pocket. Based on these calculations and comparison with a previously determined X-ray crystal structure of the C73S-O(2) form of DHP [de Serrano et al. (2007), Acta Cryst. D63, 1094-1101], it is concluded that CN(-) is gradually replaced by O(2) as crystalline DHP is photoreduced at 100 K. The ease of photoreduction of DHP A is consistent with the reduction potential, but suggests an alternative activation mechanism for DHP A compared with other peroxidases, which typically have reduction potentials that are 0.5 V more negative. The lability of CN(-) at 100 K suggests that the distal pocket of DHP A has greater flexibility than most other hemoglobins. X-ray structure of the metcyano form of dehaloperoxidase from Amphitrite ornata: evidence for photoreductive dissociation of the iron-cyanide bond.,de Serrano VS, Davis MF, Gaff JF, Zhang Q, Chen Z, D'Antonio EL, Bowden EF, Rose R, Franzen S Acta Crystallogr D Biol Crystallogr. 2010 Jul;66(Pt 7):770-82. Epub 2010 Jun 19. PMID:20606257[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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