Functional and structural variation of uridine diphosphate glycosyltransferase (UGT) gene of Stevia rebaudiana-UGTSr involved in the synthesis of rebaudioside A

► UGTSr, the gene involved in rebaudioside synthesis was characterized. ► Sequence analysis showed 48 SNPs and 39 associated amino acid substitutions. ► A unique structural pattern was revealed for UGTSr compared to other UGTs of Stevia. ► The gene was successfully expressed in plant system. ► Functional specificity of recombinant UGTSr was ascertained.