1sql
From Proteopedia
(New page: 200px<br /><applet load="1sql" size="450" color="white" frame="true" align="right" spinBox="true" caption="1sql, resolution 2.2Å" /> '''Crystal structure of ...) |
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| - | [[Image:1sql.gif|left|200px]]<br /><applet load="1sql" size=" | + | [[Image:1sql.gif|left|200px]]<br /><applet load="1sql" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1sql, resolution 2.2Å" /> | caption="1sql, resolution 2.2Å" /> | ||
'''Crystal structure of 7,8-dihydroneopterin aldolase in complex with guanine'''<br /> | '''Crystal structure of 7,8-dihydroneopterin aldolase in complex with guanine'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Dihydroneopterin aldolase (DHNA) catalyses a retroaldol reaction yielding | + | Dihydroneopterin aldolase (DHNA) catalyses a retroaldol reaction yielding 6-hydroxymethyl-7,8-dihydropterin, a biosynthetic precursor of the vitamin, tetrahydrofolate. The enzyme is a potential target for antimicrobial and anti-parasite chemotherapy. A gene specifying a dihydroneopterin aldolase from Arabidopsis thaliana was expressed in a recombinant Escherichia coli strain. The recombinant protein was purified to apparent homogeneity and crystallised using polyethylenglycol as the precipitating agent. The crystal structure was solved by X-ray diffraction analysis at 2.2A resolution. The enzyme forms a D(4)-symmetric homooctamer. Each polypeptide chain is folded into a single domain comprising an antiparallel four-stranded beta-sheet and two long alpha-helices. Four monomers are arranged in a tetrameric ring, and two of these rings form a hollow cylinder. Well defined purine derivatives are found at all eight topologically equivalent active sites. The subunit fold of the enzyme is related to substructures of dihydroneopterin triphosphate epimerase, GTP cyclohydrolase I, and pyruvoyltetrahydropterin synthase, which are all involved in the biosynthesis of pteridine type cofactors, and to urate oxidase, although some members of that superfamily have no detectable sequence similarity. Due to structural and mechanistical differences of DHNA in comparison with class I and class II aldolases, a new aldolase class is proposed. |
==About this Structure== | ==About this Structure== | ||
| - | 1SQL is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Arabidopsis_thaliana Arabidopsis thaliana] with GUN as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http:// | + | 1SQL is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Arabidopsis_thaliana Arabidopsis thaliana] with <scene name='pdbligand=GUN:'>GUN</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1SQL OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Huber, R.]] | [[Category: Huber, R.]] | ||
[[Category: Illarionova, V.]] | [[Category: Illarionova, V.]] | ||
| - | [[Category: Schott, A | + | [[Category: Schott, A K.]] |
[[Category: GUN]] | [[Category: GUN]] | ||
[[Category: aldolase classes]] | [[Category: aldolase classes]] | ||
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[[Category: tetrahydrofolate biosynthesis]] | [[Category: tetrahydrofolate biosynthesis]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:04:13 2008'' |
Revision as of 13:04, 21 February 2008
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Crystal structure of 7,8-dihydroneopterin aldolase in complex with guanine
Overview
Dihydroneopterin aldolase (DHNA) catalyses a retroaldol reaction yielding 6-hydroxymethyl-7,8-dihydropterin, a biosynthetic precursor of the vitamin, tetrahydrofolate. The enzyme is a potential target for antimicrobial and anti-parasite chemotherapy. A gene specifying a dihydroneopterin aldolase from Arabidopsis thaliana was expressed in a recombinant Escherichia coli strain. The recombinant protein was purified to apparent homogeneity and crystallised using polyethylenglycol as the precipitating agent. The crystal structure was solved by X-ray diffraction analysis at 2.2A resolution. The enzyme forms a D(4)-symmetric homooctamer. Each polypeptide chain is folded into a single domain comprising an antiparallel four-stranded beta-sheet and two long alpha-helices. Four monomers are arranged in a tetrameric ring, and two of these rings form a hollow cylinder. Well defined purine derivatives are found at all eight topologically equivalent active sites. The subunit fold of the enzyme is related to substructures of dihydroneopterin triphosphate epimerase, GTP cyclohydrolase I, and pyruvoyltetrahydropterin synthase, which are all involved in the biosynthesis of pteridine type cofactors, and to urate oxidase, although some members of that superfamily have no detectable sequence similarity. Due to structural and mechanistical differences of DHNA in comparison with class I and class II aldolases, a new aldolase class is proposed.
About this Structure
1SQL is a Single protein structure of sequence from Arabidopsis thaliana with as ligand. Full crystallographic information is available from OCA.
Reference
Biosynthesis of tetrahydrofolate in plants: crystal structure of 7,8-dihydroneopterin aldolase from Arabidopsis thaliana reveals a novel adolase class., Bauer S, Schott AK, Illarionova V, Bacher A, Huber R, Fischer M, J Mol Biol. 2004 Jun 11;339(4):967-79. PMID:15165863
Page seeded by OCA on Thu Feb 21 15:04:13 2008
