Bioinformatics of Thymidine metabolism in camels and Trypanosoma evansi: nucleoside deoxyribosyltransferase (NDRT) as a drug target
Abstract Background Trypanosoma evansi (T. evansi), the causative agent for surra or camel trypanosomiasis, is characterized by the widest geographic distribution and infects the widest range of hosts among the known trypanosomes. The recent zoonotic importance and increasing reports of drug resistance necessitate the discovery of new drug targets. Drug discovery process entails finding an interesting difference between the host and the parasite. Results In this study, the thymidine metabolic pathways were compared in camel and T. evansi. Metabolic maps, protein sequence comparisons, domain and motifs contents analysis, phylogenetic relations and 3D structure models were used in comparisons. A unique difference in thymidine metabolism was at the level of recycling of thymidine which was performed by thymidine phosphorylase in camel, while this role is T. evansi was associated with nucleoside deoxyribosyltransferase (NDRT), which is a unique enzyme for the trypanosome and was absent in camel. Thymidine in T. evansi seems to be governed by thymine through NDRT. In contrast to camel, in which thymidine can be produced from thymidylate by the action of 5'-nucleotidase. Conclusions NDRT can be regarded as a drug target against T. evansi for its strict presence in the parasite but not in the host.