GAL3ST3

Catalyzes the transfer of a sulfate group from 3'-phosphoadenylyl sulfate (PAPS) to the C-3 hydroxyl group of terminal non-reducing beta-1,4-linked galactose residues in both N-glycans and O-glycans. It acts efficiently on type 2 chains (Gal-beta-1,4-GlcNAc-R) found in N-glycans and core 2-branched O-glycans (Gal-beta-1,4-GlcNAc-beta-1,6(Gal-beta-1,3)GalNAc-R). In contrast, it shows poor activity on type 1 chains (Gal-beta-1,3-GlcNAc-R) and intermediate activity on core 1 structures (Gal-beta-1,3-GalNAc-R). Participates in the glycoconjugates sulfation namely the 3'-sulfated Lewis X epitope (Gal-beta-1,4(Fuc-alpha-1,3)GlcNAc), by sulfating N-acetyllactosamine (Gal-beta-1,4-GlcNAc) at the 3' position; then the resulting modification is fucosylated by FUT5..

Function from UniProtKB (Q96A11), read 2026-09-23. CC BY 4.0.