Study on Folate Binding Domain of Dihydrofolate Reductase in Different Plant species and Human beings

Data base (NCBI and TIGR) searches are made to retrieve protein sequences of different plant species namely Medicago truncatula,Pisum sativum, Ricinus communis, Arabidopsis thaliana, Vitis vinifera, Glycine max, Daucus carota, Oryza sativa Japonica Group,Arabidopsis lyrata subsp. lyrata, Brachypodium distachyon, Oryza sativa Indica Group, Zea mays and careful alignment of derivedsequences shows 95% or higher identity. Similarly, DHFR sequence of human being is also retrieved from NCBI. A phylogenetictree is constructed from different plant and human DHFR domain using the Neighbour – Joining method in MEGA 5.05.Conservation score is performed by using PARALINE. Result suggests that folate binding domain of dihydrofolare reductase isconserved (score 8.06) and excepting some minor variations the basic structure of the domain in both plant species and humanbeing is rather similar. Human DHFR domain contains PEKN sequence near active site, though proline is common for all theselected organisms but the other sequences are different in plants. The plant domain is always associated with TS (Thymidylatesynthase). Plant based system is predicted to be an effective model for assessment of MTX (Methotrexate) and other antifolatedrugs.