1dj5
From Proteopedia
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|PDB= 1dj5 |SIZE=350|CAPTION= <scene name='initialview01'>1dj5</scene>, resolution 1.93Å | |PDB= 1dj5 |SIZE=350|CAPTION= <scene name='initialview01'>1dj5</scene>, resolution 1.93Å | ||
|SITE= | |SITE= | ||
| - | |LIGAND= <scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene> | + | |LIGAND= <scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene>, <scene name='pdbligand=HGU:N-HYDROXYGUANIDINE'>HGU</scene> |
| - | |ACTIVITY= [http://en.wikipedia.org/wiki/Cytochrome-c_peroxidase Cytochrome-c peroxidase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.11.1.5 1.11.1.5] | + | |ACTIVITY= <span class='plainlinks'>[http://en.wikipedia.org/wiki/Cytochrome-c_peroxidase Cytochrome-c peroxidase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.11.1.5 1.11.1.5] </span> |
|GENE= | |GENE= | ||
| + | |DOMAIN= | ||
| + | |RELATEDENTRY=[[1dj1|1DJ1]] | ||
| + | |RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1dj5 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1dj5 OCA], [http://www.ebi.ac.uk/pdbsum/1dj5 PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1dj5 RCSB]</span> | ||
}} | }} | ||
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[[Category: Goodin, D B.]] | [[Category: Goodin, D B.]] | ||
[[Category: Hirst, J.]] | [[Category: Hirst, J.]] | ||
| - | [[Category: HEM]] | ||
| - | [[Category: HGU]] | ||
[[Category: cavity mutant]] | [[Category: cavity mutant]] | ||
[[Category: heme enzyme]] | [[Category: heme enzyme]] | ||
[[Category: oxidoreductase]] | [[Category: oxidoreductase]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar 30 19:42:28 2008'' |
Revision as of 16:42, 30 March 2008
| |||||||
| , resolution 1.93Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | , | ||||||
| Activity: | Cytochrome-c peroxidase, with EC number 1.11.1.5 | ||||||
| Related: | 1DJ1
| ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
CRYSTAL STRUCTURE OF R48A MUTANT OF CYTOCHROME C PEROXIDASE WITH N-HYDROXYGUANIDINE BOUND
Overview
Heme enzymes are capable of catalyzing a range of oxidative chemistry with high specificity, depending on the surrounding protein environment. We describe here a reaction catalyzed by a mutant of cytochrome c peroxidase, which is similar but distinct from those catalyzed by nitric-oxide synthase. In the R48A mutant, an expanded water-filled cavity was created above the distal heme face. N-hydroxyguanidine (NHG) but not guanidine was shown to bind in the cavity with K(d) = 8.5 mM, and coordinate to the heme to give a low spin state. Reaction of R48A with peroxide produced a Fe(IV)=O/Trp(.+) center capable of oxidizing either NHG or N(omega)-hydroxyarginine (NHA), but not arginine or guanidine, by a multi-turnover catalytic process. Oxidation of either NHG or NHA by R48A did not result in the accumulation of NO, NO(2)(-), NO(3)(-), urea, or citrulline, but instead afforded a yellow product with absorption maxima of 257 and 400 nm. Mass spectrometry of the derivatized NHA products identified the yellow species as N-nitrosoarginine. We suggest that a nitrosylating agent, possibly derived from HNO, is produced by the oxidation of one molecule of substrate. This then reacts with a second substrate molecule to form the observed N-nitroso products. This complex chemistry illustrates how the active sites of enzymes such as nitric-oxide synthase may serve to prevent alternative reactions from occurring, in addition to enabling those desired.
About this Structure
1DJ5 is a Single protein structure of sequence from Saccharomyces cerevisiae. Full crystallographic information is available from OCA.
Reference
Unusual oxidative chemistry of N(omega)-hydroxyarginine and N-hydroxyguanidine catalyzed at an engineered cavity in a heme peroxidase., Hirst J, Goodin DB, J Biol Chem. 2000 Mar 24;275(12):8582-91. PMID:10722697
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