1xhb: Difference between revisions
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[[Image:1xhb.gif|left|200px]] | [[Image:1xhb.gif|left|200px]] | ||
'''The Crystal Structure of UDP-GalNAc: polypeptide alpha-N-acetylgalactosaminyltransferase-T1''' | {{Structure | ||
|PDB= 1xhb |SIZE=350|CAPTION= <scene name='initialview01'>1xhb</scene>, resolution 2.50Å | |||
|SITE= | |||
|LIGAND= <scene name='pdbligand=MN:MANGANESE+(II)+ION'>MN</scene> and <scene name='pdbligand=CA:CALCIUM ION'>CA</scene> | |||
|ACTIVITY= [http://en.wikipedia.org/wiki/Polypeptide_N-acetylgalactosaminyltransferase Polypeptide N-acetylgalactosaminyltransferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.4.1.41 2.4.1.41] | |||
|GENE= Galnt1 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=10090 Mus musculus]) | |||
}} | |||
'''The Crystal Structure of UDP-GalNAc: polypeptide alpha-N-acetylgalactosaminyltransferase-T1''' | |||
==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
1XHB is a [ | 1XHB is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Mus_musculus Mus musculus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1XHB OCA]. | ||
==Reference== | ==Reference== | ||
The beginnings of mucin biosynthesis: the crystal structure of UDP-GalNAc:polypeptide alpha-N-acetylgalactosaminyltransferase-T1., Fritz TA, Hurley JH, Trinh LB, Shiloach J, Tabak LA, Proc Natl Acad Sci U S A. 2004 Oct 26;101(43):15307-12. Epub 2004 Oct 14. PMID:[http:// | The beginnings of mucin biosynthesis: the crystal structure of UDP-GalNAc:polypeptide alpha-N-acetylgalactosaminyltransferase-T1., Fritz TA, Hurley JH, Trinh LB, Shiloach J, Tabak LA, Proc Natl Acad Sci U S A. 2004 Oct 26;101(43):15307-12. Epub 2004 Oct 14. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/15486088 15486088] | ||
[[Category: Mus musculus]] | [[Category: Mus musculus]] | ||
[[Category: Polypeptide N-acetylgalactosaminyltransferase]] | [[Category: Polypeptide N-acetylgalactosaminyltransferase]] | ||
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[[Category: glycosyltransferase-a (gt-a)]] | [[Category: glycosyltransferase-a (gt-a)]] | ||
''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 15:09:51 2008'' | ||
Revision as of 13:09, 20 March 2008
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| 1xhb, resolution 2.50Å | |||||||||||||
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| Ligands: | MN and CA | ||||||||||||
| Gene: | Galnt1 (Mus musculus) | ||||||||||||
| Activity: | Polypeptide N-acetylgalactosaminyltransferase, with EC number 2.4.1.41 | ||||||||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||||||||
The Crystal Structure of UDP-GalNAc: polypeptide alpha-N-acetylgalactosaminyltransferase-T1
Overview
UDP-GalNAc:polypeptide alpha-N-acetylgalactosaminyltransferases (ppGaNTases) initiate the formation of mucin-type, O-linked glycans by catalyzing the transfer of alpha-N-acetylgalactosamine from UDP-GalNAc to Ser or Thr residues of core proteins to form the Tn antigen (GalNAc-alpha-1-O-Ser/Thr). ppGaNTases are unique among glycosyltransferases in containing a C-terminal lectin domain. We present the x-ray crystal structure of a ppGaNTase, murine ppGaNTase-T1, and show that it folds to form distinct catalytic and lectin domains. The association of the two domains forms a large cleft in the surface of the enzyme that contains a Mn2+ ion complexed by invariant D209 and H211 of the "DXH" motif and by invariant H344. Each of the three potential lectin domain carbohydrate-binding sites (alpha, beta, and gamma) is located on the active-site face of the enzyme, suggesting a mechanism by which the transferase may accommodate multiple conformations of glycosylated acceptor substrates. A model of a mucin 1 glycopeptide substrate bound to the enzyme shows that the spatial separation between the lectin alpha site and a modeled active site UDP-GalNAc is consistent with the in vitro pattern of glycosylation observed for this peptide catalyzed by ppGaNTase-T1. The structure also provides a template for the larger ppGaNTase family, and homology models of several ppGaNTase isoforms predict dramatically different surface chemistries consistent with isoform-selective acceptor substrate recognition.
About this Structure
1XHB is a Single protein structure of sequence from Mus musculus. Full crystallographic information is available from OCA.
Reference
The beginnings of mucin biosynthesis: the crystal structure of UDP-GalNAc:polypeptide alpha-N-acetylgalactosaminyltransferase-T1., Fritz TA, Hurley JH, Trinh LB, Shiloach J, Tabak LA, Proc Natl Acad Sci U S A. 2004 Oct 26;101(43):15307-12. Epub 2004 Oct 14. PMID:15486088
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