Lumped glycosyltransferase reactions in Oag 50 repeat unit formation
2.0 gdpmann_c + uacgam_c + udcdpgalnac_c + gdpcol_c ⇌ 3.0 gdp_c + udp_c + udcdpgalnac_a13_gal_b1_3_b13_gal_a12_c