2zdp: Difference between revisions
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[[Image: | ==Crystal structure of IsdI in complex with Cobalt protoporphyrin IX== | ||
<StructureSection load='2zdp' size='340' side='right' caption='[[2zdp]], [[Resolution|resolution]] 1.50Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[2zdp]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Staphylococcus_aureus Staphylococcus aureus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2ZDP OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2ZDP FirstGlance]. <br> | |||
</td></tr><tr><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=COH:PROTOPORPHYRIN+IX+CONTAINING+CO'>COH</scene><br> | |||
<tr><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[2zdo|2zdo]], [[1xbw|1xbw]], [[1sqe|1sqe]]</td></tr> | |||
<tr><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">isdI ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=1280 Staphylococcus aureus])</td></tr> | |||
<tr><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Heme_oxygenase Heme oxygenase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.14.99.3 1.14.99.3] </span></td></tr> | |||
<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=2zdp FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2zdp OCA], [http://www.rcsb.org/pdb/explore.do?structureId=2zdp RCSB], [http://www.ebi.ac.uk/pdbsum/2zdp 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/zd/2zdp_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 == | |||
IsdG and IsdI are paralogous proteins that are intracellular components of a complex heme uptake system in Staphylococcus aureus. IsdG and IsdI were shown previously to reductively degrade hemin. Crystal structures of the apoproteins show that these proteins belong to a newly identified heme degradation family distinct from canonical eukaryotic and prokaryotic heme oxygenases. Here we report the crystal structures of an inactive N7A variant of IsdG in complex with Fe(3+)-protoporphyrin IX (IsdG-hemin) and of IsdI in complex with cobalt protoporphyrin IX (IsdI-CoPPIX) to 1.8 A or better resolution. These structures show that the metalloporphyrins are buried into similar deep clefts such that the propionic acids form salt bridges to two Arg residues. His(77) (IsdG) or His(76) (IsdI), a critical residue required for activity, is coordinated to the Fe(3+) or Co(3+) atoms, respectively. The bound porphyrin rings form extensive steric interactions in the binding cleft such that the rings are highly distorted from the plane. This distortion is best described as ruffled and places the beta- and delta-meso carbons proximal to the distal oxygen-binding site. In the IsdG-hemin structure, Fe(3+) is pentacoordinate, and the distal side is occluded by the side chain of Ile(55). However, in the structure of IsdI-CoPPIX, the distal side of the CoPPIX accommodates a chloride ion in a cavity formed through a conformational change in Ile(55). The chloride ion participates in a hydrogen bond to the side chain amide of Asn(6). Together the structures suggest a reaction mechanism in which a reactive peroxide intermediate proceeds with nucleophilic oxidation at the beta- or delta-meso carbon of the hemin. | |||
Ruffling of metalloporphyrins bound to IsdG and IsdI, two heme-degrading enzymes in Staphylococcus aureus.,Lee WC, Reniere ML, Skaar EP, Murphy ME J Biol Chem. 2008 Nov 7;283(45):30957-63. Epub 2008 Aug 19. PMID:18713745<ref>PMID:18713745</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
==See Also== | ==See Also== | ||
*[[Heme oxygenase|Heme oxygenase]] | *[[Heme oxygenase|Heme oxygenase]] | ||
*[[Monooxygenase|Monooxygenase]] | |||
== | == References == | ||
< | <references/> | ||
__TOC__ | |||
</StructureSection> | |||
[[Category: Heme oxygenase]] | [[Category: Heme oxygenase]] | ||
[[Category: Staphylococcus aureus]] | [[Category: Staphylococcus aureus]] | ||
Revision as of 11:53, 29 September 2014
Crystal structure of IsdI in complex with Cobalt protoporphyrin IXCrystal structure of IsdI in complex with Cobalt protoporphyrin IX
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 PubMedIsdG and IsdI are paralogous proteins that are intracellular components of a complex heme uptake system in Staphylococcus aureus. IsdG and IsdI were shown previously to reductively degrade hemin. Crystal structures of the apoproteins show that these proteins belong to a newly identified heme degradation family distinct from canonical eukaryotic and prokaryotic heme oxygenases. Here we report the crystal structures of an inactive N7A variant of IsdG in complex with Fe(3+)-protoporphyrin IX (IsdG-hemin) and of IsdI in complex with cobalt protoporphyrin IX (IsdI-CoPPIX) to 1.8 A or better resolution. These structures show that the metalloporphyrins are buried into similar deep clefts such that the propionic acids form salt bridges to two Arg residues. His(77) (IsdG) or His(76) (IsdI), a critical residue required for activity, is coordinated to the Fe(3+) or Co(3+) atoms, respectively. The bound porphyrin rings form extensive steric interactions in the binding cleft such that the rings are highly distorted from the plane. This distortion is best described as ruffled and places the beta- and delta-meso carbons proximal to the distal oxygen-binding site. In the IsdG-hemin structure, Fe(3+) is pentacoordinate, and the distal side is occluded by the side chain of Ile(55). However, in the structure of IsdI-CoPPIX, the distal side of the CoPPIX accommodates a chloride ion in a cavity formed through a conformational change in Ile(55). The chloride ion participates in a hydrogen bond to the side chain amide of Asn(6). Together the structures suggest a reaction mechanism in which a reactive peroxide intermediate proceeds with nucleophilic oxidation at the beta- or delta-meso carbon of the hemin. Ruffling of metalloporphyrins bound to IsdG and IsdI, two heme-degrading enzymes in Staphylococcus aureus.,Lee WC, Reniere ML, Skaar EP, Murphy ME J Biol Chem. 2008 Nov 7;283(45):30957-63. Epub 2008 Aug 19. PMID:18713745[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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