6cp4: Difference between revisions
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== | ==P450CAM D251N MUTANT== | ||
<StructureSection load='6cp4' size='340' side='right'caption='[[6cp4]], [[Resolution|resolution]] 1.90Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[6cp4]] is a 1 chain structure with sequence from [https://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]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6CP4 FirstGlance]. <br> | |||
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.9Å</td></tr> | |||
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CAM:CAMPHOR'>CAM</scene>, <scene name='pdbligand=GOL:GLYCEROL'>GOL</scene>, <scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene>, <scene name='pdbligand=K:POTASSIUM+ION'>K</scene></td></tr> | |||
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=6cp4 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6cp4 OCA], [https://pdbe.org/6cp4 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6cp4 RCSB], [https://www.ebi.ac.uk/pdbsum/6cp4 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6cp4 ProSAT]</span></td></tr> | |||
</table> | |||
== Function == | |||
[https://www.uniprot.org/uniprot/CPXA_PSEPU CPXA_PSEPU] Involved in a camphor oxidation system. | |||
== 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/cp/6cp4_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/main_output.php?pdb_ID=6cp4 ConSurf]. | |||
<div style="clear:both"></div> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
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. | 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. | ||
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<ref>PMID:9649301</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
[[Category: | <div class="pdbe-citations 6cp4" style="background-color:#fffaf0;"></div> | ||
==See Also== | |||
*[[Cytochrome P450 3D structures|Cytochrome P450 3D structures]] | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
[[Category: Large Structures]] | |||
[[Category: Pseudomonas putida]] | [[Category: Pseudomonas putida]] | ||
[[Category: Li H]] | |||
[[Category: Li | [[Category: Poulos TL]] | ||
[[Category: Poulos | |||
Latest revision as of 09:52, 9 August 2023
P450CAM D251N MUTANTP450CAM D251N MUTANT
Structural highlights
FunctionCPXA_PSEPU Involved in a camphor oxidation system. 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 PubMedProton 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. 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[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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