1xk0: Difference between revisions

Revision as of 15:07, 3 May 2008

Crystal Structures of the G139A, G139A-NO and G143H Mutants of Human Heme Oxygenase-1

OverviewOverview

Conserved glycines, Gly139 and Gly143, in the distal helix of human heme oxygenase-1 (HO-1) provide the flexibility required for the opening and closing of the heme active site for substrate binding and product dissociation during HO-1 catalysis. Earlier mutagenesis work on human HO-1 showed that replacement of either Gly139 or Gly143 suppresses heme oxygenase activity and, in the case of the Gly139 mutants, increases peroxidase activity (Liu et al. in J. Biol. Chem. 275:34501, 2000). To further investigate the role of the conserved distal helix glycines, we have determined the crystal structures of the human HO-1 G139A mutant, the G139A mutant in a complex with NO, and the G143H mutant at 1.88, 2.18 and 2.08 A, respectively. The results confirm that fine tuning of the previously noted active-site hydrogen-bonding network is critical in determining whether heme oxygenase or peroxidase activity is observed.

About this StructureAbout this Structure

1XK0 is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.

ReferenceReference

Crystal structures of the G139A, G139A-NO and G143H mutants of human heme oxygenase-1. A finely tuned hydrogen-bonding network controls oxygenase versus peroxidase activity., Lad L, Koshkin A, de Montellano PR, Poulos TL, J Biol Inorg Chem. 2005 Mar;10(2):138-46. Epub 2005 Feb 3. PMID:15690204 Page seeded by OCA on Sat May 3 15:07:43 2008

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OCA

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 [[Image:1xk0.gif|left|200px]]
- {{Structure
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+The line below this paragraph, containing "STRUCTURE_1xk0", creates the "Structure Box" on the page.
-|SITE=
+You may change the PDB parameter (which sets the PDB file loaded into the applet)
-|LIGAND= <scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene>, <scene name='pdbligand=NO:NITROGEN+OXIDE'>NO</scene>
+or the SCENE parameter (which sets the initial scene displayed when the page is loaded),
-|ACTIVITY= <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>
+or leave the SCENE parameter empty for the default display.
-|GENE= HMOX1, HO1, HO ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=9606 Homo sapiens])
+-->
-|DOMAIN=
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-|RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1xk0 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1xk0 OCA], [http://www.ebi.ac.uk/pdbsum/1xk0 PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1xk0 RCSB]</span>
-}}
 '''Crystal Structures of the G139A, G139A-NO and G143H Mutants of Human Heme Oxygenase-1'''
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 [[Category: Montellano, P R.Ortiz de.]]
 [[Category: Poulos, T L.]]
-[[Category: heme]]
+[[Category: Heme]]
-[[Category: heme degredation]]
+[[Category: Heme degredation]]
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May  3 15:07:43 2008''
-''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Mon Mar 31 00:50:40 2008''