O-antigen group O:28ac polymerase yielding a very long O antigen chain length (100 repeat units)
100.0 udcpdpgalnac_b1_4_glc_b1_3_gal3_a1_4_rmn_a1_3_qui3nac_p ⇌ 99.0 udcpdp_p + OA28ac_VL_p