Figure 1From: Active site plasticity revealed from the structure of the enterobacterial N-ribohydrolase RihA bound to a competitive inhibitorLigands of the E. coli pyrimidine-preferring NH RihA. A) Uridine and B) cytidine, the natural substrates. C) The competitive inhibitor DAPIR. The iminoribitol moiety resembles the features of the transition state of the hydrolytic reaction, including a partial double bond character of the C1'-O4' bond, an elongated N-glycosidic bond, and a partial positive charge at the sugar ring.Back to article page