1i3k: Difference between revisions
No edit summary |
No edit summary |
||
| Line 1: | Line 1: | ||
[[Image:1i3k.jpg|left|200px]] | [[Image:1i3k.jpg|left|200px]] | ||
'''MOLECULAR BASIS FOR SEVERE EPIMERASE-DEFICIENCY GALACTOSEMIA: X-RAY STRUCTURE OF THE HUMAN V94M-SUBSTITUTED UDP-GALACTOSE 4-EPIMERASE''' | {{Structure | ||
|PDB= 1i3k |SIZE=350|CAPTION= <scene name='initialview01'>1i3k</scene>, resolution 1.50Å | |||
|SITE= | |||
|LIGAND= <scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=NAD:NICOTINAMIDE-ADENINE-DINUCLEOTIDE'>NAD</scene>, <scene name='pdbligand=UPG:URIDINE-5'-DIPHOSPHATE-GLUCOSE'>UPG</scene> and <scene name='pdbligand=EDO:1,2-ETHANEDIOL'>EDO</scene> | |||
|ACTIVITY= [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] | |||
|GENE= HGALE ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=9606 Homo sapiens]) | |||
}} | |||
'''MOLECULAR BASIS FOR SEVERE EPIMERASE-DEFICIENCY GALACTOSEMIA: X-RAY STRUCTURE OF THE HUMAN V94M-SUBSTITUTED UDP-GALACTOSE 4-EPIMERASE''' | |||
==Overview== | ==Overview== | ||
| Line 10: | Line 19: | ||
==About this Structure== | ==About this Structure== | ||
1I3K is a [ | 1I3K is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1I3K OCA]. | ||
==Reference== | ==Reference== | ||
Molecular basis for severe epimerase deficiency galactosemia. X-ray structure of the human V94m-substituted UDP-galactose 4-epimerase., Thoden JB, Wohlers TM, Fridovich-Keil JL, Holden HM, J Biol Chem. 2001 Jun 8;276(23):20617-23. Epub 2001 Mar 7. PMID:[http:// | Molecular basis for severe epimerase deficiency galactosemia. X-ray structure of the human V94m-substituted UDP-galactose 4-epimerase., Thoden JB, Wohlers TM, Fridovich-Keil JL, Holden HM, J Biol Chem. 2001 Jun 8;276(23):20617-23. Epub 2001 Mar 7. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/11279193 11279193] | ||
[[Category: Homo sapiens]] | [[Category: Homo sapiens]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| Line 28: | Line 37: | ||
[[Category: galactosemia epimerase short-chain dehydrogenase]] | [[Category: galactosemia epimerase short-chain dehydrogenase]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 11:45:11 2008'' | ||
Revision as of 12:45, 20 March 2008
| |||||||
| , resolution 1.50Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | , , , and | ||||||
| Gene: | HGALE (Homo sapiens) | ||||||
| Activity: | UDP-glucose 4-epimerase, with EC number 5.1.3.2 | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
MOLECULAR BASIS FOR SEVERE EPIMERASE-DEFICIENCY GALACTOSEMIA: X-RAY STRUCTURE OF THE HUMAN V94M-SUBSTITUTED UDP-GALACTOSE 4-EPIMERASE
OverviewOverview
Galactosemia is an inherited disorder characterized by an inability to metabolize galactose. Although classical galactosemia results from impairment of the second enzyme of the Leloir pathway, namely galactose-1-phosphate uridylyltransferase, alternate forms of the disorder can occur due to either galactokinase or UDP-galactose 4-epimerase deficiencies. One of the more severe cases of epimerase deficiency galactosemia arises from an amino acid substitution at position 94. It has been previously demonstrated that the V94M protein is impaired relative to the wild-type enzyme predominantly at the level of V(max) rather than K(m). To address the molecular consequences the mutation imparts on the three-dimensional architecture of the enzyme, we have solved the structures of the V94M-substituted human epimerase complexed with NADH and UDP-glucose, UDP-galactose, UDP-GlcNAc, or UDP-GalNAc. In the wild-type enzyme, the hydrophobic side chain of Val(94) packs near the aromatic group of the catalytic Tyr(157) and serves as a molecular "fence" to limit the rotation of the glycosyl portions of the UDP-sugar substrates within the active site. The net effect of the V94M substitution is an opening up of the Ala(93) to Glu(96) surface loop, which allows free rotation of the sugars into nonproductive binding modes.
DiseaseDisease
Known disease associated with this structure: Galactose epimerase deficiency OMIM:[606953]
About this StructureAbout this Structure
1I3K is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.
ReferenceReference
Molecular basis for severe epimerase deficiency galactosemia. X-ray structure of the human V94m-substituted UDP-galactose 4-epimerase., Thoden JB, Wohlers TM, Fridovich-Keil JL, Holden HM, J Biol Chem. 2001 Jun 8;276(23):20617-23. Epub 2001 Mar 7. PMID:11279193
Page seeded by OCA on Thu Mar 20 11:45:11 2008