6cp4: Difference between revisions
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[[Image:6cp4.gif|left|200px]] | [[Image:6cp4.gif|left|200px]] | ||
'''P450CAM D251N MUTANT''' | {{Structure | ||
|PDB= 6cp4 |SIZE=350|CAPTION= <scene name='initialview01'>6cp4</scene>, resolution 1.9Å | |||
|SITE= <scene name='pdbsite=K:K+Binding+Site'>K</scene> | |||
|LIGAND= <scene name='pdbligand=K:POTASSIUM+ION'>K</scene>, <scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene>, <scene name='pdbligand=CAM:CAMPHOR'>CAM</scene> and <scene name='pdbligand=GOL:GLYCEROL'>GOL</scene> | |||
|ACTIVITY= [http://en.wikipedia.org/wiki/Camphor_5-monooxygenase Camphor 5-monooxygenase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.14.15.1 1.14.15.1] | |||
|GENE= | |||
}} | |||
'''P450CAM D251N MUTANT''' | |||
==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
6CP4 is a [ | 6CP4 is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Pseudomonas_putida Pseudomonas putida]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6CP4 OCA]. | ||
==Reference== | ==Reference== | ||
Understanding the role of the essential Asp251 in cytochrome p450cam using site-directed mutagenesis, crystallography, and kinetic solvent isotope effect., Vidakovic M, Sligar SG, Li H, Poulos TL, Biochemistry. 1998 Jun 30;37(26):9211-9. PMID:[http:// | Understanding the role of the essential Asp251 in cytochrome p450cam using site-directed mutagenesis, crystallography, and kinetic solvent isotope effect., Vidakovic M, Sligar SG, Li H, Poulos TL, Biochemistry. 1998 Jun 30;37(26):9211-9. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/9649301 9649301] | ||
[[Category: Camphor 5-monooxygenase]] | [[Category: Camphor 5-monooxygenase]] | ||
[[Category: Pseudomonas putida]] | [[Category: Pseudomonas putida]] | ||
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[[Category: p450]] | [[Category: p450]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 19:13:20 2008'' | ||
Revision as of 20:13, 20 March 2008
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| , resolution 1.9Å | |||||||
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| Sites: | |||||||
| Ligands: | , , and | ||||||
| Activity: | Camphor 5-monooxygenase, with EC number 1.14.15.1 | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
P450CAM D251N MUTANT
OverviewOverview
Proton transfer in cytochromes P450 is a critical step in the activation of molecular oxygen. Extensive study of the P450cam active site has identified several residues that play a central role in dioxygen bond scission. A highly conserved carboxylate, aspartate-251 in P450cam in the distal helix I, participates in a series of hydrogen-bond/ion pairs near the molecular surface and has been implicated in the catalytic mechanism. Mutation of Asp251 is known to lower activity by 2 orders of magnitude and change the rate-limiting step in the catalytic cycle, suggesting a role for an acid functionality in generation of iron-oxygen reactive intermediates. The turnover rates of the Asp251Asn mutant in various protium-deuterium mixtures have been determined and show a significantly larger kinetic solvent isotope effect, with an overall magnitude of 10 compared to 1.8 for the wild-type P450cam. In addition, a much larger number of protons are involved in the rate-limiting step for the Asp251Asn mutant than in the wild-type enzyme. These results indicate that Asp251 is an essential part of the normal proton delivery machinery required for O-O bond scission. The crystal structure of the Aps251Asn mutant obtained from data collected at cryogenic temperatures has been refined to 1.9 A. Key hydrogen bonds required to hold Asp251 in position have been broken which allows the mutant Asn251 side chain to swing out and away from the O2 binding site leading to a more open active site. This change could allow easier access by water and thus contribute to the observed kinetic solvent isotope effects.
About this StructureAbout this Structure
6CP4 is a Single protein structure of sequence from Pseudomonas putida. Full crystallographic information is available from OCA.
ReferenceReference
Understanding the role of the essential Asp251 in cytochrome p450cam using site-directed mutagenesis, crystallography, and kinetic solvent isotope effect., Vidakovic M, Sligar SG, Li H, Poulos TL, Biochemistry. 1998 Jun 30;37(26):9211-9. PMID:9649301
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