1orr
From Proteopedia
(New page: 200px<br /><applet load="1orr" size="450" color="white" frame="true" align="right" spinBox="true" caption="1orr, resolution 1.50Å" /> '''Crystal Structure of...) |
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| - | [[Image:1orr.jpg|left|200px]]<br /><applet load="1orr" size=" | + | [[Image:1orr.jpg|left|200px]]<br /><applet load="1orr" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1orr, resolution 1.50Å" /> | caption="1orr, resolution 1.50Å" /> | ||
'''Crystal Structure of CDP-Tyvelose 2-Epimerase complexed with NAD and CDP'''<br /> | '''Crystal Structure of CDP-Tyvelose 2-Epimerase complexed with NAD and CDP'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Tyvelose epimerase catalyzes the last step in the biosynthesis of tyvelose | + | Tyvelose epimerase catalyzes the last step in the biosynthesis of tyvelose by converting CDP-d-paratose to CDP-d-tyvelose. This unusual 3,6-dideoxyhexose occurs in the O-antigens of some types of Gram-negative bacteria. Here we describe the cloning, protein purification, and high-resolution x-ray crystallographic analysis of tyvelose epimerase from Salmonella typhi complexed with CDP. The enzyme from S. typhi is a homotetramer with each subunit containing 339 amino acid residues and a tightly bound NAD+ cofactor. The quaternary structure of the enzyme displays 222 symmetry and can be aptly described as a dimer of dimers. Each subunit folds into two distinct lobes: the N-terminal motif responsible for NAD+ binding and the C-terminal region that harbors the binding site for CDP. The analysis described here demonstrates that tyvelose epimerase belongs to the short-chain dehydrogenase/reductase superfamily of enzymes. Indeed, its active site is reminiscent to that observed for UDP-galactose 4-epimerase, an enzyme that plays a key role in galactose metabolism. Unlike UDP-galactose 4-epimerase where the conversion of configuration occurs about C-4 of the UDP-glucose or UDP-galactose substrates, in the reaction catalyzed by tyvelose epimerase, the inversion of stereochemistry occurs at C-2. On the basis of the observed binding mode for CDP, it is possible to predict the manner in which the substrate, CDP-paratose, and the product, CDP-tyvelose, might be accommodated within the active site of tyvelose epimerase. |
==About this Structure== | ==About this Structure== | ||
| - | 1ORR is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Salmonella_typhi Salmonella typhi] with NAD and CDP as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | + | 1ORR is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Salmonella_typhi Salmonella typhi] with <scene name='pdbligand=NAD:'>NAD</scene> and <scene name='pdbligand=CDP:'>CDP</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1ORR OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Salmonella typhi]] | [[Category: Salmonella typhi]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Holden, H | + | [[Category: Holden, H M.]] |
| - | [[Category: Koropatkin, N | + | [[Category: Koropatkin, N M.]] |
[[Category: Liu, H.]] | [[Category: Liu, H.]] | ||
[[Category: CDP]] | [[Category: CDP]] | ||
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[[Category: short-chain dehydrogenase/reductase]] | [[Category: short-chain dehydrogenase/reductase]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:21:00 2008'' |
Revision as of 12:21, 21 February 2008
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Crystal Structure of CDP-Tyvelose 2-Epimerase complexed with NAD and CDP
Overview
Tyvelose epimerase catalyzes the last step in the biosynthesis of tyvelose by converting CDP-d-paratose to CDP-d-tyvelose. This unusual 3,6-dideoxyhexose occurs in the O-antigens of some types of Gram-negative bacteria. Here we describe the cloning, protein purification, and high-resolution x-ray crystallographic analysis of tyvelose epimerase from Salmonella typhi complexed with CDP. The enzyme from S. typhi is a homotetramer with each subunit containing 339 amino acid residues and a tightly bound NAD+ cofactor. The quaternary structure of the enzyme displays 222 symmetry and can be aptly described as a dimer of dimers. Each subunit folds into two distinct lobes: the N-terminal motif responsible for NAD+ binding and the C-terminal region that harbors the binding site for CDP. The analysis described here demonstrates that tyvelose epimerase belongs to the short-chain dehydrogenase/reductase superfamily of enzymes. Indeed, its active site is reminiscent to that observed for UDP-galactose 4-epimerase, an enzyme that plays a key role in galactose metabolism. Unlike UDP-galactose 4-epimerase where the conversion of configuration occurs about C-4 of the UDP-glucose or UDP-galactose substrates, in the reaction catalyzed by tyvelose epimerase, the inversion of stereochemistry occurs at C-2. On the basis of the observed binding mode for CDP, it is possible to predict the manner in which the substrate, CDP-paratose, and the product, CDP-tyvelose, might be accommodated within the active site of tyvelose epimerase.
About this Structure
1ORR is a Single protein structure of sequence from Salmonella typhi with and as ligands. Full crystallographic information is available from OCA.
Reference
High resolution x-ray structure of tyvelose epimerase from Salmonella typhi., Koropatkin NM, Liu HW, Holden HM, J Biol Chem. 2003 Jun 6;278(23):20874-81. Epub 2003 Mar 17. PMID:12642575
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