PMID: 16650853

 

    Legend: Gene, Sites

Title : Structural basis of carbohydrate transfer activity by human UDP-GalNAc: polypeptide alpha-N-acetylgalactosaminyltransferase (pp-GalNAc-T10)

Abstract :

1. Mucin-type O-glycans are important carbohydrate chains involved in differentiation and malignant transformation
2. Biosynthesis of the O-glycan is initiated by the transfer of N-acetylgalactosamine (GalNAc) which is catalyzed by UDP-GalNAc:polypeptide alpha-N-acetylgalactosaminyltransferases (pp-GalNAc-Ts)
3. Here we present crystal structures of the pp-GalNAc-T10 isozyme, which has specificity for glycosylated peptides , in complex with the hydrolyzed donor substrate UDP-GalNAc and in complex with GalNAc- serine
4. A structural comparison with uncomplexed pp-GalNAc-T1 suggests that substantial conformational changes occur in two loops near the catalytic center upon donor substrate binding, and that a distinct interdomain arrangement between the catalytic and lectin domains forms a narrow cleft for acceptor substrates
5. The distance between the catalytic center and the carbohydrate-binding site on the lectin beta sub-domain influences the position of GalNAc glycosylation on GalNAc-glycosylated peptide substrates
6. A chimeric enzyme in which the two domains of pp-GalNAc-T10 are connected by a linker from pp-GalNAc-T1 acquires activity toward non-glycosylated acceptors, identifying a potential mechanism for generating the various acceptor specificities in different isozymes to produce a wide range of O-glycans

Output (sent_index, trigger, protein, sugar, site):

• 3. glycosylated, , -, -, peptides
• 5. GalNAc-glycosylated, , -, GalNAc-glycosylated peptide substrates, -
• 5. peptide, , -, GalNAc-glycosylated peptide substrates, -
• 5. position, , -, GalNAc-glycosylated peptide substrates, position
• 5. site, , -, the lectin beta sub-domain, sub-domain

Output(Part-Of) (sent_index, protein, site):

*Output_Site_Fusion* (sent_index, protein, sugar, site):

 

Protein	NCBI ID	SENTENCE INDEX