1tw1
From Proteopedia
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|PDB= 1tw1 |SIZE=350|CAPTION= <scene name='initialview01'>1tw1</scene>, resolution 2.30Å | |PDB= 1tw1 |SIZE=350|CAPTION= <scene name='initialview01'>1tw1</scene>, resolution 2.30Å | ||
|SITE= | |SITE= | ||
| - | |LIGAND= <scene name='pdbligand=GDU:GALACTOSE-URIDINE-5'-DIPHOSPHATE'>GDU</scene>, <scene name='pdbligand= | + | |LIGAND= <scene name='pdbligand=DIO:1,4-DIETHYLENE+DIOXIDE'>DIO</scene>, <scene name='pdbligand=GDU:GALACTOSE-URIDINE-5'-DIPHOSPHATE'>GDU</scene>, <scene name='pdbligand=MES:2-(N-MORPHOLINO)-ETHANESULFONIC+ACID'>MES</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene> |
|ACTIVITY= | |ACTIVITY= | ||
|GENE= B4GALT1 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=9913 Bos taurus]) | |GENE= B4GALT1 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=9913 Bos taurus]) | ||
| + | |DOMAIN= | ||
| + | |RELATEDENTRY=[[1o0r|1O0R]] | ||
| + | |RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1tw1 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1tw1 OCA], [http://www.ebi.ac.uk/pdbsum/1tw1 PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1tw1 RCSB]</span> | ||
}} | }} | ||
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[[Category: Qasba, P K.]] | [[Category: Qasba, P K.]] | ||
[[Category: Ramakrishnan, B.]] | [[Category: Ramakrishnan, B.]] | ||
| - | [[Category: | + | [[Category: closed conformation]] |
| - | [[Category: | + | [[Category: met344his mutation]] |
| - | [[Category: | + | [[Category: mn binding]] |
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| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Mon Mar 31 00:01:56 2008'' |
Revision as of 21:01, 30 March 2008
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| , resolution 2.30Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | , , , , | ||||||
| Gene: | B4GALT1 (Bos taurus) | ||||||
| Related: | 1O0R
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| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
beta-1,4-galactosyltransferase mutant Met344His (m344H-Gal-T1) complex with UDP-galactose and magnesium
Overview
Beta-1,4-galactosyltransferase (beta4Gal-T1) in the presence of manganese ion transfers galactose from UDP-galactose (UDP-Gal) to N-acetylglucosamine (GlcNAc) that is either free or linked to an oligosaccharide. Crystallographic studies on bovine beta4Gal-T1 have shown that the primary metal binding site is located in the hinge region of a long flexible loop, which upon Mn(2+) and UDP-Gal binding changes from an open to a closed conformation. This conformational change creates an oligosaccharide binding site in the enzyme. Neither UDP nor UDP analogues efficiently induce these conformational changes in the wild-type enzyme, thereby restricting the structural analysis of the acceptor binding site. The binding of Mn(2+) involves an uncommon coordination to the Sdelta atom of Met344; when it is mutated to His, the mutant M344H, in the presence of Mn(2+) and UDP-hexanolamine, readily changes to a closed conformation, facilitating the structural analysis of the enzyme bound with an oligosaccharide acceptor. Although the mutant M344H loses 98% of its Mn(2+)-dependent activity, it exhibits 25% of its activity in the presence of Mg(2+). The crystal structures of M344H-Gal-T1 in complex with either UDP-Gal.Mn(2+) or UDP-Gal.Mg(2+), determined at 2.3 A resolution, show that the mutant enzyme in these complexes is in a closed conformation, and the coordination stereochemistry of Mg(2+) is quite similar to that of Mn(2+). Although either Mn(2+) or Mg(2+), together with UDP-Gal, binds and changes the conformation of the M344H mutant to the closed one, it is the Mg(2+) complex that engages efficiently in catalyses. Thus, this property enabled us to crystallize the M344H mutant for the first time with the acceptor substrate chitobiose in the presence of UDP-hexanolamine and Mn(2+). The crystal structure determined at 2.3 A resolution reveals that the GlcNAc residue at the nonreducing end of chitobiose makes extensive hydrophobic interactions with the highly conserved Tyr286 residue.
About this Structure
1TW1 is a Single protein structure of sequence from Bos taurus. Full crystallographic information is available from OCA.
Reference
Effect of the Met344His mutation on the conformational dynamics of bovine beta-1,4-galactosyltransferase: crystal structure of the Met344His mutant in complex with chitobiose., Ramakrishnan B, Boeggeman E, Qasba PK, Biochemistry. 2004 Oct 5;43(39):12513-22. PMID:15449940
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