1lrk: Difference between revisions
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'''Crystal Structure of Escherichia coli UDP-Galactose 4-Epimerase Mutant Y299C Complexed with UDP-N-acetylglucosamine''' | {{Structure | ||
|PDB= 1lrk |SIZE=350|CAPTION= <scene name='initialview01'>1lrk</scene>, resolution 1.75Å | |||
|SITE= | |||
|LIGAND= <scene name='pdbligand=NA:SODIUM+ION'>NA</scene>, <scene name='pdbligand=NAD:NICOTINAMIDE-ADENINE-DINUCLEOTIDE'>NAD</scene>, <scene name='pdbligand=UD1:URIDINE-DIPHOSPHATE-N-ACETYLGLUCOSAMINE'>UD1</scene> and <scene name='pdbligand=PGE:TRIETHYLENE GLYCOL'>PGE</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= GALE ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=562 Escherichia coli]) | |||
}} | |||
'''Crystal Structure of Escherichia coli UDP-Galactose 4-Epimerase Mutant Y299C Complexed with UDP-N-acetylglucosamine''' | |||
==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
1LRK is a [ | 1LRK is a [[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=1LRK OCA]. | ||
==Reference== | ==Reference== | ||
Structural analysis of the Y299C mutant of Escherichia coli UDP-galactose 4-epimerase. Teaching an old dog new tricks., Thoden JB, Henderson JM, Fridovich-Keil JL, Holden HM, J Biol Chem. 2002 Jul 26;277(30):27528-34. Epub 2002 May 17. PMID:[http:// | Structural analysis of the Y299C mutant of Escherichia coli UDP-galactose 4-epimerase. Teaching an old dog new tricks., Thoden JB, Henderson JM, Fridovich-Keil JL, Holden HM, J Biol Chem. 2002 Jul 26;277(30):27528-34. Epub 2002 May 17. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/12019271 12019271] | ||
[[Category: Escherichia coli]] | [[Category: Escherichia coli]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
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[[Category: short chain dehydrogenase]] | [[Category: 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 12:34:20 2008'' | ||
Revision as of 13:34, 20 March 2008
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| , resolution 1.75Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | , , and | ||||||
| Gene: | GALE (Escherichia coli) | ||||||
| Activity: | UDP-glucose 4-epimerase, with EC number 5.1.3.2 | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Crystal Structure of Escherichia coli UDP-Galactose 4-Epimerase Mutant Y299C Complexed with UDP-N-acetylglucosamine
OverviewOverview
UDP-galactose 4-epimerase catalyzes the interconversion of UDP-Gal and UDP-Glc during normal galactose metabolism. The mammalian form of the enzyme, unlike its Escherichia coli counterpart, can also interconvert UDP-GalNAc and UDP-GlcNAc. One key feature of the epimerase reaction mechanism is the rotation of a 4-ketopyranose intermediate in the active site. By comparing the high resolution x-ray structures of both the bacterial and human forms of the enzyme, it was previously postulated that the additional activity in the human epimerase was due to replacement of the structural equivalent of Tyr-299 in the E. coli enzyme with a cysteine residue, thereby leading to a larger active site volume. To test this hypothesis, the Y299C mutant form of the E. coli enzyme was prepared and its three-dimensional structure solved as described here. Additionally, the Y299C mutant protein was assayed for activity against both UDP-Gal and UDP-GalNAc. These studies have revealed that, indeed, this simple mutation did confer UDP-GalNAc/UDP-GlcNAc converting activity to the bacterial enzyme with minimal changes in its three-dimensional structure. Specifically, although the Y299C mutation in the bacterial enzyme resulted in a loss of epimerase activity with regard to UDP-Gal by almost 5-fold, it resulted in a gain of activity against UDP-GalNAc by more than 230-fold.
About this StructureAbout this Structure
1LRK is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.
ReferenceReference
Structural analysis of the Y299C mutant of Escherichia coli UDP-galactose 4-epimerase. Teaching an old dog new tricks., Thoden JB, Henderson JM, Fridovich-Keil JL, Holden HM, J Biol Chem. 2002 Jul 26;277(30):27528-34. Epub 2002 May 17. PMID:12019271
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