2gak: Difference between revisions

Revision as of 18:29, 21 February 2008

X-ray crystal structure of murine leukocyte-type Core 2 b1,6-N-acetylglucosaminyltransferase (C2GnT-L)

OverviewOverview

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 StructureAbout this Structure

2GAK is a Single protein structure of sequence from Mus musculus with as ligand. 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.

ReferenceReference

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

Page seeded by OCA on Thu Feb 21 17:29:48 2008

Proteopedia Page Contributors and Editors (what is this?)Proteopedia Page Contributors and Editors (what is this?)

OCA

@@ Line 1: / Line 1: @@
-[[Image:2gak.gif|left|200px]]<br /><applet load="2gak" size="450" color="white" frame="true" align="right" spinBox="true"
+[[Image:2gak.gif|left|200px]]<br /><applet load="2gak" size="350" color="white" frame="true" align="right" spinBox="true"
 caption="2gak, resolution 2.0&Aring;" />
 '''X-ray crystal structure of murine leukocyte-type Core 2 b1,6-N-acetylglucosaminyltransferase (C2GnT-L)'''<br />
 ==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.
+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==
-GAK is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Mus_musculus Mus musculus] with NAG as [http://en.wikipedia.org/wiki/ligand ligand]. 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://ispc.weizmann.ac.il/oca-bin/ocashort?id=2GAK OCA].
+GAK is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Mus_musculus Mus musculus] with <scene name='pdbligand=NAG:'>NAG</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. 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=2GAK OCA].
 ==Reference==
@@ Line 14: / Line 14: @@
 [[Category: Mus musculus]]
 [[Category: Single protein]]
-[[Category: Pak, J.E.]]
+[[Category: Pak, J E.]]
-[[Category: Rini, J.M.]]
+[[Category: Rini, J M.]]
 [[Category: NAG]]
 [[Category: cis-peptide]]
@@ Line 21: / Line 21: @@
 [[Category: glycoprotein]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Wed Nov 21 11:04:54 2007''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 17:29:48 2008''