2gam
From Proteopedia
(New page: 200px<br /><applet load="2gam" size="450" color="white" frame="true" align="right" spinBox="true" caption="2gam, resolution 2.7Å" /> '''X-ray crystal structu...) |
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| - | [[Image:2gam.gif|left|200px]]<br /><applet load="2gam" size=" | + | [[Image:2gam.gif|left|200px]]<br /><applet load="2gam" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="2gam, resolution 2.7Å" /> | caption="2gam, resolution 2.7Å" /> | ||
'''X-ray crystal structure of murine leukocyte-type Core 2 b1,6-N-acetylglucosaminyltransferase (C2GnT-L) in complex with Galb1,3GalNAc'''<br /> | '''X-ray crystal structure of murine leukocyte-type Core 2 b1,6-N-acetylglucosaminyltransferase (C2GnT-L) in complex with Galb1,3GalNAc'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Leukocyte type core 2 beta1,6-N-acetylglucosaminyltransferase (C2GnT-L) is | + | Leukocyte type core 2 beta1,6-N-acetylglucosaminyltransferase (C2GnT-L) is a key enzyme in the biosynthesis of branched O-glycans. It is an inverting, metal ion-independent family 14 glycosyltransferase that catalyzes the formation of the core 2 O-glycan (Galbeta1-3[GlcNAcbeta1-6]GalNAc-O-Ser/Thr) from its donor and acceptor substrates, UDP-GlcNAc and the core 1 O-glycan (Galbeta1-3GalNAc-O-Ser/Thr), respectively. Reported here are the x-ray crystal structures of murine C2GnT-L in the absence and presence of the acceptor substrate Galbeta1-3GalNAc at 2.0 and 2.7A resolution, respectively. C2GnT-L was found to possess the GT-A fold; however, it lacks the characteristic metal ion binding DXD motif. The Galbeta1-3GalNAc complex defines the determinants of acceptor substrate binding and shows that Glu-320 corresponds to the structurally conserved catalytic base found in other inverting GT-A fold glycosyltransferases. Comparison of the C2GnT-L structure with that of other GT-A fold glycosyltransferases further suggests that Arg-378 and Lys-401 serve to electrostatically stabilize the nucleoside diphosphate leaving group, a role normally played by metal ion in GT-A structures. The use of basic amino acid side chains in this way is strikingly similar to that seen in a number of metal ion-independent GT-B fold glycosyltransferases and suggests a convergence of catalytic mechanism shared by both GT-A and GT-B fold glycosyltransferases. |
==About this Structure== | ==About this Structure== | ||
| - | 2GAM is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Mus_musculus Mus musculus]. Active as [http://en.wikipedia.org/wiki/Beta-1,3-galactosyl-O-glycosyl-glycoprotein_beta-1,6-N-_acetylglucosaminyltransferase Beta-1,3-galactosyl-O-glycosyl-glycoprotein beta-1,6-N- acetylglucosaminyltransferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.4.1.102 2.4.1.102] Full crystallographic information is available from [http:// | + | 2GAM is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Mus_musculus Mus musculus]. Active as [http://en.wikipedia.org/wiki/Beta-1,3-galactosyl-O-glycosyl-glycoprotein_beta-1,6-N-_acetylglucosaminyltransferase Beta-1,3-galactosyl-O-glycosyl-glycoprotein beta-1,6-N- acetylglucosaminyltransferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.4.1.102 2.4.1.102] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2GAM OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Mus musculus]] | [[Category: Mus musculus]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Pak, J | + | [[Category: Pak, J E.]] |
| - | [[Category: Rini, J | + | [[Category: Rini, J M.]] |
[[Category: cis-peptide]] | [[Category: cis-peptide]] | ||
[[Category: dimer]] | [[Category: dimer]] | ||
[[Category: glycoprotein]] | [[Category: glycoprotein]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 17:29:49 2008'' |
Revision as of 15:29, 21 February 2008
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X-ray crystal structure of murine leukocyte-type Core 2 b1,6-N-acetylglucosaminyltransferase (C2GnT-L) in complex with Galb1,3GalNAc
Overview
Leukocyte type core 2 beta1,6-N-acetylglucosaminyltransferase (C2GnT-L) is a key enzyme in the biosynthesis of branched O-glycans. It is an inverting, metal ion-independent family 14 glycosyltransferase that catalyzes the formation of the core 2 O-glycan (Galbeta1-3[GlcNAcbeta1-6]GalNAc-O-Ser/Thr) from its donor and acceptor substrates, UDP-GlcNAc and the core 1 O-glycan (Galbeta1-3GalNAc-O-Ser/Thr), respectively. Reported here are the x-ray crystal structures of murine C2GnT-L in the absence and presence of the acceptor substrate Galbeta1-3GalNAc at 2.0 and 2.7A resolution, respectively. C2GnT-L was found to possess the GT-A fold; however, it lacks the characteristic metal ion binding DXD motif. The Galbeta1-3GalNAc complex defines the determinants of acceptor substrate binding and shows that Glu-320 corresponds to the structurally conserved catalytic base found in other inverting GT-A fold glycosyltransferases. Comparison of the C2GnT-L structure with that of other GT-A fold glycosyltransferases further suggests that Arg-378 and Lys-401 serve to electrostatically stabilize the nucleoside diphosphate leaving group, a role normally played by metal ion in GT-A structures. The use of basic amino acid side chains in this way is strikingly similar to that seen in a number of metal ion-independent GT-B fold glycosyltransferases and suggests a convergence of catalytic mechanism shared by both GT-A and GT-B fold glycosyltransferases.
About this Structure
2GAM is a Single protein structure of sequence from Mus musculus. Active as Beta-1,3-galactosyl-O-glycosyl-glycoprotein beta-1,6-N- acetylglucosaminyltransferase, with EC number 2.4.1.102 Full crystallographic information is available from OCA.
Reference
X-ray crystal structure of leukocyte type core 2 beta1,6-N-acetylglucosaminyltransferase. Evidence for a convergence of metal ion-independent glycosyltransferase mechanism., Pak JE, Arnoux P, Zhou S, Sivarajah P, Satkunarajah M, Xing X, Rini JM, J Biol Chem. 2006 Sep 8;281(36):26693-701. Epub 2006 Jul 7. PMID:16829524
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