Protein
Polypeptide N-acetylgalactosaminyltransferase 5
Organism
Drosophila melanogaster
Function
Catalyzes the initial reaction in O-linked oligosaccharide biosynthesis, the transfer of an N-acetyl-D-galactosamine residue to a serine or threonine residue on the protein receptor (PubMed:12829714, PubMed:18669915). It can both act as a peptide transferase that transfers GalNAc onto unmodified peptide substrates, and as a glycopeptide transferase that requires the prior addition of a GalNAc on a peptide before adding additional GalNAc moieties. Prefers EA2 as substrate (PubMed:12829714). In the larval midgut, required for O-glycosylation of apical and luminal proteins within copper cells enabling proper gut acidification (PubMed:22157008).
Similarity
Belongs to the glycosyltransferase 2 family. GalNAc-T subfamily.
Sequence
MTFSTFTRKMRGRMRSNTCRIVLLTSLVWVIFDFVLIARYSDCIGKDGWRCKRSGEYDVELPNAERLVDDNQLVDDNEINTEKSLDGESGGALIMGQGFASGGISMTYPSVVLKKWFLAPSVQEAKGKPGEMGKPVKIPADMKDLMKEKFKENQFNLLASDMISLNRSLTDVRHEGCRRKHYASKLPTTSIVIVFHNEAWTTLLRTVWSVINRSPRALLKEIILVDDASERDFLGKQLEEYVAKLPVKTFVLRTEKRSGLIRARLLGAEHVSGEVITFLDAHCECTEGWLEPLLARIVQNRRTVVCPIIDVISDETFEYITASDSTWGGFNWKLNFRWYRVPSREMARRNNDRTAPLRTPTMAGGLFSIDKDYFYEIGSYDEGMDIWGGENLEMSFRIWQCGGILEIIPCSHVGHVFRDKSPYTFPGGVAKIVLHNAARVAEVWLDEWRDFYYSMSTGARKASAGDVSDRKALRDRLKCKSFRWYLENVYPESLMPLDYYYLGEIRNAETETCLDTMGRKYNEKVGISYCHGLGGNQVFAYTKRQQIMSDDLCLDASSSNGPVNMVRCHNMGGNQEWVYDAEEKWIRHTNTGQCLQRATRDDANTPLLRPCSYGKGQQWLMESKFKWQAH