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[[ | ==Structure of E530Q variant of E. coli KatE== | ||
<StructureSection load='4ens' size='340' side='right' caption='[[4ens]], [[Resolution|resolution]] 1.60Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[4ens]] is a 4 chain structure with sequence from [http://en.wikipedia.org/wiki/Escherichia_coli_k-12 Escherichia coli k-12]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4ENS OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4ENS FirstGlance]. <br> | |||
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=HDD:CIS-HEME+D+HYDROXYCHLORIN+GAMMA-SPIROLACTONE'>HDD</scene>, <scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene></td></tr> | |||
<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[4enp|4enp]], [[4enq|4enq]], [[4enr|4enr]], [[4ent|4ent]], [[4enu|4enu]], [[4env|4env]], [[4enw|4enw]]</td></tr> | |||
<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">b1732, JW1721, katE ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=83333 Escherichia coli K-12])</td></tr> | |||
<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Catalase Catalase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.11.1.6 1.11.1.6] </span></td></tr> | |||
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4ens FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4ens OCA], [http://www.rcsb.org/pdb/explore.do?structureId=4ens RCSB], [http://www.ebi.ac.uk/pdbsum/4ens PDBsum]</span></td></tr> | |||
</table> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
The main channel for H(2)O(2) access to the heme cavity in large subunit catalases is twice as long as in small subunit catalases and is divided into two distinct parts. Like small subunit catalases, the 15A of the channel adjacent to the heme has a predominantly hydrophobic surface with only weak water occupancy, but the next 15A extending to the protein surface is hydrophilic and contains a complex water matrix in multiple passages. At the approximate junction of these two sections are a conserved serine and glutamate that are hydrogen bonded and associated with H(2)O(2) in inactive variants. Mutation of these residues changed the dimensions of the channel, both enlarging and constricting it, and also changed the solvent occupancy in the hydrophobic, inner section of the main channel. Despite these structural changes and the prominent location of the residues in the channel, the variants exhibited less than a 2-fold change in the k(cat) and apparent K(M) kinetic constants. These results reflect the importance of the complex multi-passage structure of the main channel. Surprisingly, mutation of either the serine or glutamate to an aliphatic side chain interfered with heme oxidation to heme d. | |||
Influence of main channel structure on H(2)O(2) access to the heme cavity of catalase KatE of Escherichia coli.,Jha V, Chelikani P, Carpena X, Fita I, Loewen PC Arch Biochem Biophys. 2012 Oct 1;526(1):54-9. doi: 10.1016/j.abb.2012.06.010., Epub 2012 Jul 20. PMID:22820098<ref>PMID:22820098</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
==See Also== | ==See Also== | ||
*[[Catalase|Catalase]] | *[[Catalase|Catalase]] | ||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
[[Category: Catalase]] | [[Category: Catalase]] | ||
[[Category: Escherichia coli k-12]] | [[Category: Escherichia coli k-12]] | ||
[[Category: Jha, V | [[Category: Jha, V]] | ||
[[Category: Loewen, P C | [[Category: Loewen, P C]] | ||
[[Category: E530q variant]] | [[Category: E530q variant]] | ||
[[Category: Heme orientation]] | [[Category: Heme orientation]] | ||
[[Category: Oxidoreductase]] | [[Category: Oxidoreductase]] | ||
Revision as of 19:13, 9 December 2014
Structure of E530Q variant of E. coli KatEStructure of E530Q variant of E. coli KatE
Structural highlights
Publication Abstract from PubMedThe main channel for H(2)O(2) access to the heme cavity in large subunit catalases is twice as long as in small subunit catalases and is divided into two distinct parts. Like small subunit catalases, the 15A of the channel adjacent to the heme has a predominantly hydrophobic surface with only weak water occupancy, but the next 15A extending to the protein surface is hydrophilic and contains a complex water matrix in multiple passages. At the approximate junction of these two sections are a conserved serine and glutamate that are hydrogen bonded and associated with H(2)O(2) in inactive variants. Mutation of these residues changed the dimensions of the channel, both enlarging and constricting it, and also changed the solvent occupancy in the hydrophobic, inner section of the main channel. Despite these structural changes and the prominent location of the residues in the channel, the variants exhibited less than a 2-fold change in the k(cat) and apparent K(M) kinetic constants. These results reflect the importance of the complex multi-passage structure of the main channel. Surprisingly, mutation of either the serine or glutamate to an aliphatic side chain interfered with heme oxidation to heme d. Influence of main channel structure on H(2)O(2) access to the heme cavity of catalase KatE of Escherichia coli.,Jha V, Chelikani P, Carpena X, Fita I, Loewen PC Arch Biochem Biophys. 2012 Oct 1;526(1):54-9. doi: 10.1016/j.abb.2012.06.010., Epub 2012 Jul 20. PMID:22820098[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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