title: Nucleoside deoxyribosyltransferase-II from Lactobacillus helveticus Substrate specificity studied. Pyrimidine bases as acceptors.
abstract: The nucleoside deoxyribosyltransferase (nucleoside:purine (pyrimidine) deoxyribosyltransferase, EC 2.4.2.6) fraction catalyzing specifically the transfer of the deoxyribosyl moiety from a purine (or a pyrimidine) to a pyrimidine (or a purine) exhibits a broad specificity for the acceptor base. With a pyrimidine base as the acceptor a -OH or -SH group adjacent to the N-1 atom is essential. A substituent on position 6 hinders the reaction. On positions 4 and 5 various substituent were found to influence the reaction rate and some of them give non-competent substrates. A few anomalous cases are also discussed in relation with the role of N-3. Deoxyribonucleosides can also be obtained with non-pyrimidine rings.
mesh_terms: D002384:Catalysis; D003853:Deoxyribonucleosides; D007778:Lactobacillus / Q000201:enzymology*; D010430:Pentosyltransferases / Q000378:metabolism*; D011741:Pyrimidine Nucleosides / Q000378:metabolism*; D013379:Substrate Specificity
chemical_list: D003853:Deoxyribonucleosides; D011741:Pyrimidine Nucleosides; D010430:Pentosyltransferases; C021888:nucleoside deoxyribosyltransferase