UDPGT is of major importance in the conjugation and subsequent elimination of potentially toxic xenobiotics and endogenous compounds. Conjugates small planar phenolic molecules such as 4-nitrophenol, 1-naphthol, and 4-methylumbelliferone. The bulky phenol 4-hydroxybiphenyl, androgens and estrogens are not substrates. 2-hydroxybiphenyl is an excellent substrate. glucuronate acceptor + UDP-alpha-D-glucuronate = acceptor beta-D-glucuronoside + H(+) + UDP A number of isoforms may be produced. Isoforms may have a different N-terminal domain and a common C-terminal domain of 245 residues. By dioxin. Belongs to the UDP-glycosyltransferase family.