sentences:  The following three examples illustrate how the inhibitors mimic the transition state structure by changing functional groups correspond to the geometry and electrostatic distribution of the transition state structures.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.