This is an N-terminal domain found in pyrimidine/purine nucleotide 5'-monophosphate nucleosidases (PpnN) in bacteria. PpnN catalyzes the hydrolysis of the N-glycosidic bond of diverse pyrimidine and purine nucleotide 5'-monophosphates, to form ribose 5-phosphate and the corresponding free base. It can use AMP, GMP, IMP, CMP, dTMP and UMP as substrates [1]. It is found in association with Pfam:PF03641 and Pfam:PF11892.

1: Nontargeted in vitro metabolomics for high-throughput identification of novel enzymes in Escherichia coli. Sevin DC, Fuhrer T, Zamboni N, Sauer U; Nat Methods. 2017;14:187-194. PMID:27941785