【摘要】 根据锤头型核酶的作用模式 ,设计、合成和克隆了特异切割苹果锈果类病毒ASSVd正链 (194- 196位点 )或负链 (89- 91位点 )RNA的 2个短臂锤头型核酶基因 :42nt的RzASSVd(+)和 40nt的RzASSVd(- )。经转录获得核酶转录物和3 2 P标记的ASSVd正、负链转录物。将核酶与ASSVd混合 ,5 0℃或 37℃保温 3～ 4h ,进行 8%PAGE(含8mol L尿素 )和放射自显影分析。体外切割检测表明 :2个核酶均具有特异切割活性 ,其中RzASSVd(- )对ASSVd负链的切割活性较高 ,对ASSVd正链不起作用。RzASSVd(+)对ASSVd正链的切割活性较弱 ,对ASSVd负链亦不起作用。在此基础上 ,构建得到双价核酶基因pGEMRzASSVd(± )。更多还原

【Abstract】 The genes of short armed hammerhead ribozyme targeting against two sites on positive strand (194-196) and negative strand (89-91) of ASSVd were designed, synthesized and cloned according to the action manner of hammerhead ribozyme. The full lengths of the genes are 42bp (RzASSVd(+))and 40bp (RzASSVd(-)). After transcription in vitro,the ASSVd positive and negative RNA labeled with 32P were mixed with the ribozyme transcript and incubated 3～4 h at 50℃ or 37℃. The results were assayed on 8% PAGE (containing 8mol/L urea) and autoradiogrammed. As predicted, the transcript of the active RzASSVd(-) could cleave the ASSVd negative strand RNA with a high activity but had no cleavage effect on the ASSVd positive strand. The transcript of the RzASSVd(+) gene could cleave the ASSVd positive strand but its cleavage activity was very low. As the same, it cannot cleave the negative strand either. On the base of the result, we construct dimmer ribozyme gene pGEMRzASSVd(±) containing both RzASSVd(+) and RzASSVd(-).更多还原