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1hzj
From Proteopedia
(New page: 200px<br /> <applet load="1hzj" size="450" color="white" frame="true" align="right" spinBox="true" caption="1hzj, resolution 1.5Å" /> '''HUMAN UDP-GALACTOSE ...) |
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| - | [[Image:1hzj.gif|left|200px]]<br /> | + | [[Image:1hzj.gif|left|200px]]<br /><applet load="1hzj" size="350" color="white" frame="true" align="right" spinBox="true" |
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caption="1hzj, resolution 1.5Å" /> | caption="1hzj, resolution 1.5Å" /> | ||
'''HUMAN UDP-GALACTOSE 4-EPIMERASE: ACCOMMODATION OF UDP-N-ACETYLGLUCOSAMINE WITHIN THE ACTIVE SITE'''<br /> | '''HUMAN UDP-GALACTOSE 4-EPIMERASE: ACCOMMODATION OF UDP-N-ACETYLGLUCOSAMINE WITHIN THE ACTIVE SITE'''<br /> | ||
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==About this Structure== | ==About this Structure== | ||
| - | 1HZJ 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 CL, MG, NAD and UD1 as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/UDP-glucose_4-epimerase UDP-glucose 4-epimerase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=5.1.3.2 5.1.3.2] Full crystallographic information is available from [http:// | + | 1HZJ 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=CL:'>CL</scene>, <scene name='pdbligand=MG:'>MG</scene>, <scene name='pdbligand=NAD:'>NAD</scene> and <scene name='pdbligand=UD1:'>UD1</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/UDP-glucose_4-epimerase UDP-glucose 4-epimerase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=5.1.3.2 5.1.3.2] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1HZJ OCA]. |
==Reference== | ==Reference== | ||
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[[Category: short-chain dehydrogenase]] | [[Category: short-chain dehydrogenase]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri Feb 15 15:58:50 2008'' |
Revision as of 13:58, 15 February 2008
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HUMAN UDP-GALACTOSE 4-EPIMERASE: ACCOMMODATION OF UDP-N-ACETYLGLUCOSAMINE WITHIN THE ACTIVE SITE
Contents |
Overview
UDP-galactose 4-epimerase catalyzes the interconversion of UDP-galactose, and UDP-glucose during normal galactose metabolism. One of the key, structural features in the proposed reaction mechanism for the enzyme is, the rotation of a 4'-ketopyranose intermediate within the active site, pocket. Recently, the three-dimensional structure of the human enzyme with, bound NADH and UDP-glucose was determined. Unlike that observed for the, protein isolated from Escherichia coli, the human enzyme can also turn, over UDP-GlcNAc to UDP-GalNAc and vice versa. Here we describe the, three-dimensional structure of human epimerase complexed with NADH and, UDP-GlcNAc. To accommodate the additional N-acetyl group at the C2, position of the sugar, the side chain of Asn-207 rotates toward the, interior of the protein and interacts with Glu-199. Strikingly, in the, human enzyme, the structural equivalent of Tyr-299 in the E. coli protein, is replaced with a cysteine residue (Cys-307) and the active site volume, for the human protein is calculated to be approximately 15% larger than, that observed for the bacterial epimerase. This combination of a larger, active site cavity and amino acid residue replacement most likely accounts, for the inability of the E. coli enzyme to interconvert UDP-GlcNAc and, UDP-GalNAc.
Disease
Known disease associated with this structure: Galactose epimerase deficiency OMIM:[606953]
About this Structure
1HZJ is a Single protein structure of sequence from Homo sapiens with , , and as ligands. Active as UDP-glucose 4-epimerase, with EC number 5.1.3.2 Full crystallographic information is available from OCA.
Reference
Human UDP-galactose 4-epimerase. Accommodation of UDP-N-acetylglucosamine within the active site., Thoden JB, Wohlers TM, Fridovich-Keil JL, Holden HM, J Biol Chem. 2001 May 4;276(18):15131-6. Epub 2001 Jan 26. PMID:11279032
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