1h4j
From Proteopedia
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| - | [[Image:1h4j.gif|left|200px]] | + | [[Image:1h4j.gif|left|200px]] |
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| - | '''METHYLOBACTERIUM EXTORQUENS METHANOL DEHYDROGENASE D303E MUTANT''' | + | {{Structure |
| + | |PDB= 1h4j |SIZE=350|CAPTION= <scene name='initialview01'>1h4j</scene>, resolution 3.0Å | ||
| + | |SITE= <scene name='pdbsite=AC1:Pqq+Binding+Site+For+Chain+A'>AC1</scene>, <scene name='pdbsite=AC2:Ca+Binding+Site+For+Chain+A'>AC2</scene>, <scene name='pdbsite=AC3:Pqq+Binding+Site+For+Chain+C'>AC3</scene>, <scene name='pdbsite=AC5:Pqq+Binding+Site+For+Chain+E'>AC5</scene>, <scene name='pdbsite=AC6:Ca+Binding+Site+For+Chain+E'>AC6</scene>, <scene name='pdbsite=AC7:Pqq+Binding+Site+For+Chain+G'>AC7</scene> and <scene name='pdbsite=AC8:Ca+Binding+Site+For+Chain+G'>AC8</scene> | ||
| + | |LIGAND= <scene name='pdbligand=CA:CALCIUM+ION'>CA</scene> and <scene name='pdbligand=PQQ:PYRROLOQUINOLINE QUINONE'>PQQ</scene> | ||
| + | |ACTIVITY= [http://en.wikipedia.org/wiki/Alcohol_dehydrogenase_(acceptor) Alcohol dehydrogenase (acceptor)], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.1.99.8 1.1.99.8] | ||
| + | |GENE= | ||
| + | }} | ||
| + | |||
| + | '''METHYLOBACTERIUM EXTORQUENS METHANOL DEHYDROGENASE D303E MUTANT''' | ||
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==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
| - | 1H4J is a [ | + | 1H4J is a [[Protein complex]] structure of sequences from [http://en.wikipedia.org/wiki/Methylobacterium_extorquens Methylobacterium extorquens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1H4J OCA]. |
==Reference== | ==Reference== | ||
| - | Site-directed mutagenesis and X-ray crystallography of the PQQ-containing quinoprotein methanol dehydrogenase and its electron acceptor, cytochrome c(L)., Afolabi PR, Mohammed F, Amaratunga K, Majekodunmi O, Dales SL, Gill R, Thompson D, Cooper JB, Wood SP, Goodwin PM, Anthony C, Biochemistry. 2001 Aug 21;40(33):9799-809. PMID:[http:// | + | Site-directed mutagenesis and X-ray crystallography of the PQQ-containing quinoprotein methanol dehydrogenase and its electron acceptor, cytochrome c(L)., Afolabi PR, Mohammed F, Amaratunga K, Majekodunmi O, Dales SL, Gill R, Thompson D, Cooper JB, Wood SP, Goodwin PM, Anthony C, Biochemistry. 2001 Aug 21;40(33):9799-809. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/11502173 11502173] |
[[Category: Alcohol dehydrogenase (acceptor)]] | [[Category: Alcohol dehydrogenase (acceptor)]] | ||
[[Category: Methylobacterium extorquens]] | [[Category: Methylobacterium extorquens]] | ||
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[[Category: quinoprotein]] | [[Category: quinoprotein]] | ||
| - | ''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 11:32:07 2008'' |
Revision as of 09:32, 20 March 2008
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| , resolution 3.0Å | |||||||
|---|---|---|---|---|---|---|---|
| Sites: | , , , , , and | ||||||
| Ligands: | and | ||||||
| Activity: | Alcohol dehydrogenase (acceptor), with EC number 1.1.99.8 | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
METHYLOBACTERIUM EXTORQUENS METHANOL DEHYDROGENASE D303E MUTANT
Overview
Two proteins specifically involved in methanol oxidation in the methylotrophic bacterium Methylobacterium extorquens have been modified by site-directed mutagenesis. Mutation of the proposed active site base (Asp303) to glutamate in methanol dehydrogenase (MDH) gave an active enzyme (D303E-MDH) with a greatly reduced affinity for substrate and with a lower activation energy. Results of kinetic and deuterium isotope studies showed that the essential mechanism in the mutant protein was unchanged, and that the step requiring activation by ammonia remained rate limiting. No spectrally detectable intermediates could be observed during the reaction. The X-ray structure, determined to 3 A resolution, of D303E-MDH showed that the position and coordination geometry of the Ca2+ ion in the active site was altered; the larger Glu303 side chain was coordinated to the Ca2+ ion and also hydrogen bonded to the O5 atom of pyrroloquinoline quinone (PQQ). The properties and structure of the D303E-MDH are consistent with the previous proposal that the reaction in MDH is initiated by proton abstraction involving Asp303, and that the mechanism involves a direct hydride transfer reaction. Mutation of the two adjacent cysteine residues that make up the novel disulfide ring in the active site of MDH led to an inactive enzyme, confirming the essential role of this remarkable ring structure. Mutations of cytochrome c(L), which is the electron acceptor from MDH was used to identify Met109 as the sixth ligand to the heme.
About this Structure
1H4J is a Protein complex structure of sequences from Methylobacterium extorquens. Full crystallographic information is available from OCA.
Reference
Site-directed mutagenesis and X-ray crystallography of the PQQ-containing quinoprotein methanol dehydrogenase and its electron acceptor, cytochrome c(L)., Afolabi PR, Mohammed F, Amaratunga K, Majekodunmi O, Dales SL, Gill R, Thompson D, Cooper JB, Wood SP, Goodwin PM, Anthony C, Biochemistry. 2001 Aug 21;40(33):9799-809. PMID:11502173
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