InterPro domain: IPR035902

The nucleoside phosphorylase and the phosphoribosyltransferase catalytic domain belongs to the glycosyl transferase family. The glycosyl transferase family includes anthranilate phosphoribosyltransferase (TrpD, 2.4.2.18 ) and thymidine phosphorylase ( 2.4.2.2 ). All these proteins can transfer a phosphorylated ribose substrate. Thymidine phosphorylase ( 2.4.2.2 ) catalyses the reversible phosphorolysis of thymidine, deoxyuridine and their analogues to their respective bases and 2-deoxyribose 1-phosphate. This enzyme regulates the availability of thymidine and is therefore essential to nucleic acid metabolism.

The structure is composed of three layers (alpha/beta/alpha) arranged in parallel beta-sheets of five strands.