A recombinant plasmid pE,T-racd was first constructed by cloning osRACD, the development-regulating gene that controls photoperiod fertility transformation in the photoperiod sensitive genie male sterile rice Nongken 58S, into a prokaryote expression vector pET28a( + ). It was then transformed into E. coli BL-21. Cutting with thrombin of the fusion protein extracted from transformants and PAGE separation yielded pure osRACD protein, which was further concentrated using ultrafiltration and renatured using glutathione oxidation/reduction refolding system for later functional study. As demonstrated by in vitro functional assay, the osRACD protein expressed in E . coli B-21 shows remarkable activity in binding GTP specifically and hydrolyzing it. A recombinant plasmid pE, T-racd was first constructed by cloning osRACD, the development-regulating gene that controls photoperiod fertility transformation in the photoperiod sensitive genie male sterile rice Nongken 58S, into a prokaryote expression vector pET28a (+). It was then transformed into further E. coli BL-21. Cutting with thrombin of the fusion protein extracted from transformants and PAGE separation yielded pure osRACD protein, which was further concentrated using ultrafiltration and renatured using glutathione oxidation / reduction refolding system for later functional study. vitro functional assay, the osRACD protein expressed in E. coli B-21 shows remarkable activity in binding GTP specifically and hydrolyzing it.