Although b-glucuronidases from many species have been registered in Genbank, only a few genes have been published for GL biotransformation [18] . Three fungal strains, namely, A. terreus Li-20, P. purpurogenum Li-3, and A. ustus Li-62, were screened in our previous studies and represented three modes of GL biotransformation: (1) GLRGA+GAMG; (2) GLRGAMG; and (3) GLRGA [9] . The three b-glucuronidase genes were cloned in our laboratory, and the aa sequence alignment showed that the bglucuronidase from A. terreus Li-20 (AtGUS) was quite different from the other two b-glucuronidases(PGUS and AuGUS) in Cterminal non-conservative sequence. AtGUS can hydrolyze GL into two products; thus, the different modes of GL biotransformation of the b-glucuronidases from the other two fungi may be related to the natural evolution in the sequence. In the present research, Atgus and the partial sequence [Atgus(-3t)] without Cterminal non-conservative sequence behind the TIM barrel domain were amplified in order to investigate effects of nonconservative sequence on enzymatic property.