2icj
From Proteopedia
(New page: 200px<br /><applet load="2icj" size="450" color="white" frame="true" align="right" spinBox="true" caption="2icj, resolution 1.7Å" /> '''The crystal structure...) |
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| - | [[Image:2icj.jpg|left|200px]]<br /><applet load="2icj" size=" | + | [[Image:2icj.jpg|left|200px]]<br /><applet load="2icj" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="2icj, resolution 1.7Å" /> | caption="2icj, resolution 1.7Å" /> | ||
'''The crystal structure of human isopentenyl diphophate isomerase'''<br /> | '''The crystal structure of human isopentenyl diphophate isomerase'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Isopentenyl diphosphate isomerase catalyses a crucial activation step in | + | Isopentenyl diphosphate isomerase catalyses a crucial activation step in the biosynthesis of isoprenoids, one of the most ancient and diverse classes of natural products. This enzyme is responsible for an unusual isomerization of the inactive carbon-carbon double bond of isopentenyl diphosphate (IPP) to create its electrophilic allylic isomer dimethylallyl diphosphate (DMAPP). Here we report the crystal structure of human IPP isomerase at 1.7 A resolution and the complex structure with its native substrate at 1.9 A resolution. These structures reveal a mechanism wherein interconversion is catalyzed by a stereoselective antarafacial [1.3] transposition of a proton involving the indispensable residues Cys87, Glu149, Trp197 and Tyr137. A newly identified alternative conformation of Cys87 driven by Trp197 and the selectivity of different metal ions located in the active site provide further insight into the catalytic mechanism. Comparison with Escherichia coli IPP isomerase reveals a novel substrate entrance in human IPP isomerase. |
==About this Structure== | ==About this Structure== | ||
| - | 2ICJ 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 MG and SO4 as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Isopentenyl-diphosphate_Delta-isomerase Isopentenyl-diphosphate Delta-isomerase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=5.3.3.2 5.3.3.2] Full crystallographic information is available from [http:// | + | 2ICJ 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=MG:'>MG</scene> and <scene name='pdbligand=SO4:'>SO4</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Isopentenyl-diphosphate_Delta-isomerase Isopentenyl-diphosphate Delta-isomerase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=5.3.3.2 5.3.3.2] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2ICJ OCA]. |
==Reference== | ==Reference== | ||
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[[Category: human isopentenyl diphophate isomerase]] | [[Category: human isopentenyl diphophate isomerase]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 17:51:13 2008'' |
Revision as of 15:51, 21 February 2008
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The crystal structure of human isopentenyl diphophate isomerase
Overview
Isopentenyl diphosphate isomerase catalyses a crucial activation step in the biosynthesis of isoprenoids, one of the most ancient and diverse classes of natural products. This enzyme is responsible for an unusual isomerization of the inactive carbon-carbon double bond of isopentenyl diphosphate (IPP) to create its electrophilic allylic isomer dimethylallyl diphosphate (DMAPP). Here we report the crystal structure of human IPP isomerase at 1.7 A resolution and the complex structure with its native substrate at 1.9 A resolution. These structures reveal a mechanism wherein interconversion is catalyzed by a stereoselective antarafacial [1.3] transposition of a proton involving the indispensable residues Cys87, Glu149, Trp197 and Tyr137. A newly identified alternative conformation of Cys87 driven by Trp197 and the selectivity of different metal ions located in the active site provide further insight into the catalytic mechanism. Comparison with Escherichia coli IPP isomerase reveals a novel substrate entrance in human IPP isomerase.
About this Structure
2ICJ is a Single protein structure of sequence from Homo sapiens with and as ligands. Active as Isopentenyl-diphosphate Delta-isomerase, with EC number 5.3.3.2 Full crystallographic information is available from OCA.
Reference
The crystal structure of human isopentenyl diphosphate isomerase at 1.7 A resolution reveals its catalytic mechanism in isoprenoid biosynthesis., Zheng W, Sun F, Bartlam M, Li X, Li R, Rao Z, J Mol Biol. 2007 Mar 9;366(5):1447-58. Epub 2006 Dec 24. PMID:17250851
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