sentences:  Methylthioadenosine nucleosidase are enzymes that catalyse the hydrolytic deadenylation reaction of 5'-methylthioadenosine and S-adenosylhomocysteine.It is also regarded as an important target for antibacterial drug discovery because it is important in the metabolic system of bacteria and only produced by bacteria.Given the different distance between nitrogen atom of adenine and the ribose anomeric carbon (see in the diagram in this section), the transition state structure can be defined by early or late dissociation stage.