The function of ENSG00000198108 (CHSY3, chondroitin sulfate synthase 3) is as follows. Catalytic component of CHSY1-CHPF2 and CHSY1-CHPF chondroitin sulfate synthase complexes (PubMed:41298522). Has both beta-1,3- glucuronic acid and beta-1,4-N-acetylgalactosamine transferase activity. Transfers glucuronic acid (GlcUA) from UDP-GlcUA and N- acetylgalactosamine (GalNAc) from UDP-GalNAc to the non-reducing end of the elongating chondroitin polymer. Specific activity is much reduced compared to CHSY1. {ECO:0000269|PubMed:12907687, ECO:0000269|PubMed:41298522}.