2imo
From Proteopedia
(New page: 200px<br /><applet load="2imo" size="450" color="white" frame="true" align="right" spinBox="true" caption="2imo, resolution 2.80Å" /> '''Crystal structure of...) |
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| - | [[Image:2imo.gif|left|200px]]<br /><applet load="2imo" size=" | + | [[Image:2imo.gif|left|200px]]<br /><applet load="2imo" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="2imo, resolution 2.80Å" /> | caption="2imo, resolution 2.80Å" /> | ||
'''Crystal structure of allantoate amidohydrolase from Escherichia coli at pH 4.6'''<br /> | '''Crystal structure of allantoate amidohydrolase from Escherichia coli at pH 4.6'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Purine metabolism plays a major role in regulating the availability of | + | Purine metabolism plays a major role in regulating the availability of purine nucleotides destined for nucleic acid synthesis. Allantoate amidohydrolase catalyzes the conversion of allantoate to (S)-ureidoglycolate, one of the crucial alternate steps in purine metabolism. The crystal structure of a ternary complex of allantoate amidohydrolase with its substrate allantoate and an allosteric effector, a sulfate ion, from Escherichia coli was determined to understand better the catalytic mechanism and substrate specificity. The 2.25 A resolution X-ray structure reveals an alpha/beta scaffold akin to zinc exopeptidases of the peptidase M20 family and lacks the (beta/alpha)(8)-barrel fold characteristic of the amidohydrolases. Arrangement of the substrate and the two co-catalytic zinc ions at the active site governs catalytic specificity for hydrolysis of N-carbamyl versus the peptide bond in exopeptidases. In its crystalline form, allantoate amidohydrolase adopts a relatively open conformation. However, structural analysis reveals the possibility of a significant movement of domains via rotation about two hinge regions upon allosteric effector and substrate binding resulting in a closed catalytically competent conformation by bringing the substrate allantoate closer to co-catalytic zinc ions. Two cis-prolyl peptide bonds found on either side of the dimerization domain in close proximity to the substrate and ligand-binding sites may be involved in protein folding and in preserving the integrity of the catalytic site. |
==About this Structure== | ==About this Structure== | ||
| - | 2IMO is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http:// | + | 2IMO is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2IMO OCA]. |
==Reference== | ==Reference== | ||
| - | Structural | + | Structural analysis of a ternary complex of allantoate amidohydrolase from Escherichia coli reveals its mechanics., Agarwal R, Burley SK, Swaminathan S, J Mol Biol. 2007 Apr 27;368(2):450-63. Epub 2007 Feb 20. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=17362992 17362992] |
[[Category: Escherichia coli]] | [[Category: Escherichia coli]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Agarwal, R.]] | [[Category: Agarwal, R.]] | ||
| - | [[Category: Burley, S | + | [[Category: Burley, S K.]] |
| - | [[Category: NYSGXRC, New | + | [[Category: NYSGXRC, New York Structural GenomiX Research Consortium.]] |
[[Category: Swaminathan, S.]] | [[Category: Swaminathan, S.]] | ||
[[Category: allantoate amidohydrolase]] | [[Category: allantoate amidohydrolase]] | ||
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[[Category: t1507]] | [[Category: t1507]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 17:54:08 2008'' |
Revision as of 15:54, 21 February 2008
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Crystal structure of allantoate amidohydrolase from Escherichia coli at pH 4.6
Overview
Purine metabolism plays a major role in regulating the availability of purine nucleotides destined for nucleic acid synthesis. Allantoate amidohydrolase catalyzes the conversion of allantoate to (S)-ureidoglycolate, one of the crucial alternate steps in purine metabolism. The crystal structure of a ternary complex of allantoate amidohydrolase with its substrate allantoate and an allosteric effector, a sulfate ion, from Escherichia coli was determined to understand better the catalytic mechanism and substrate specificity. The 2.25 A resolution X-ray structure reveals an alpha/beta scaffold akin to zinc exopeptidases of the peptidase M20 family and lacks the (beta/alpha)(8)-barrel fold characteristic of the amidohydrolases. Arrangement of the substrate and the two co-catalytic zinc ions at the active site governs catalytic specificity for hydrolysis of N-carbamyl versus the peptide bond in exopeptidases. In its crystalline form, allantoate amidohydrolase adopts a relatively open conformation. However, structural analysis reveals the possibility of a significant movement of domains via rotation about two hinge regions upon allosteric effector and substrate binding resulting in a closed catalytically competent conformation by bringing the substrate allantoate closer to co-catalytic zinc ions. Two cis-prolyl peptide bonds found on either side of the dimerization domain in close proximity to the substrate and ligand-binding sites may be involved in protein folding and in preserving the integrity of the catalytic site.
About this Structure
2IMO is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.
Reference
Structural analysis of a ternary complex of allantoate amidohydrolase from Escherichia coli reveals its mechanics., Agarwal R, Burley SK, Swaminathan S, J Mol Biol. 2007 Apr 27;368(2):450-63. Epub 2007 Feb 20. PMID:17362992
Page seeded by OCA on Thu Feb 21 17:54:08 2008
Categories: Escherichia coli | Single protein | Agarwal, R. | Burley, S K. | NYSGXRC, New York Structural GenomiX Research Consortium. | Swaminathan, S. | Allantoate amidohydrolase | Allc | Apoenzyme | New york structural genomix research consortium | Nysgxrc | Protein structure initiative | Psi-2 | Structural genomics | T1507
