1lgd: Difference between revisions
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New page: left|200px<br /> <applet load="1lgd" size="450" color="white" frame="true" align="right" spinBox="true" caption="1lgd, resolution 1.90Å" /> '''Crystal Structure A... |
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[[Image:1lgd.gif|left|200px]]<br /> | [[Image:1lgd.gif|left|200px]]<br /><applet load="1lgd" size="350" color="white" frame="true" align="right" spinBox="true" | ||
<applet load="1lgd" size=" | |||
caption="1lgd, resolution 1.90Å" /> | caption="1lgd, resolution 1.90Å" /> | ||
'''Crystal Structure Analysis of HCA II Mutant T199P in Complex with Bicarbonate'''<br /> | '''Crystal Structure Analysis of HCA II Mutant T199P in Complex with Bicarbonate'''<br /> | ||
==Overview== | ==Overview== | ||
Substitution of Pro for Thr199 in the active site of human carbonic | Substitution of Pro for Thr199 in the active site of human carbonic anhydrase II (HCA II)(1) reduces its catalytic efficiency about 3000-fold. X-ray crystallographic structures of the T199P/C206S variant have been determined in complex with the substrate bicarbonate and with the inhibitors thiocyanate and beta-mercaptoethanol. The latter molecule is normally not an inhibitor of wild-type HCA II. All three ligands display novel binding interactions to the T199P/C206S mutant. The beta-mercaptoethanol molecule binds in the active site area with its sulfur atom tetrahedrally coordinated to the zinc ion. Thiocyanate binds tetrahedrally coordinated to the zinc ion in T199P/C206S, in contrast to its pentacoordinated binding to the zinc ion in wild-type HCA II. Bicarbonate binds to the mutant with two of its oxygens at the positions of the zinc water (Wat263) and Wat318 in wild-type HCA II. The environment of this area is more hydrophilic than the normal bicarbonate-binding site of HCA II situated in the hydrophobic part of the cavity normally occupied by the so-called deep water (Wat338). The observation of a new binding site for bicarbonate has implications for understanding the mechanism by which the main-chain amino group of Thr199 acquired an important role for orientation of the substrate during the evolution of the enzyme. | ||
==Disease== | ==Disease== | ||
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==About this Structure== | ==About this Structure== | ||
1LGD is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] with ZN and BCT as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Carbonate_dehydratase Carbonate dehydratase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.2.1.1 4.2.1.1] Full crystallographic information is available from [http:// | 1LGD is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] with <scene name='pdbligand=ZN:'>ZN</scene> and <scene name='pdbligand=BCT:'>BCT</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Carbonate_dehydratase Carbonate dehydratase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.2.1.1 4.2.1.1] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1LGD OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Huang, S.]] | [[Category: Huang, S.]] | ||
[[Category: Jonsson, B | [[Category: Jonsson, B H.]] | ||
[[Category: Sauer-Eriksson, A | [[Category: Sauer-Eriksson, A E.]] | ||
[[Category: Sjoblom, B.]] | [[Category: Sjoblom, B.]] | ||
[[Category: BCT]] | [[Category: BCT]] | ||
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[[Category: hcaii mutant t199p-bct complex]] | [[Category: hcaii mutant t199p-bct complex]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:44:41 2008'' | ||
