Functional and phylogenetic analyses of a putative Drosophila melanogaster UDP-glycosyltransferase gene

Glucosidation plays a major role in the inactivation and excretion of a great variety of both endogenous and exogenous compounds. The recent determination of the complete genome sequence of Drosophila melanogaster has revealed the presence of over 30 putative UDP-glucosyltransferase (UGT) genes in this organism. We report here the molecular cloning and functional characterisation of one of these genes, named DmUgt37a1. The predicted protein comprises 525 amino acids and has about 30% overall amino acid identity with vertebrate members of the UGT family. The phylogenetic relationships of DmUgt37a1 with other members of the UGT family from D. melanogaster are discussed. DmUgt37a1 was expressed in lepidopteran insect cells and the ability of the enzyme to conjugate 38 potential substrates belonging to diverse chemical groups was assessed using UDP-glucose as sugar-donor. However, no activity was detected with any compound under the conditions used and thus, the substrate specificity of the enzyme remains unknown.