Influence of Substrate and Ribozyme Sequences on the Functions of Ribozyme.
The mono-component ribozyme RZ1, RZ3 and RZ4 were ligated in different orders into two tri-component ribozymes RZ134 and RZ413.Both tri-component ribozymes could cleave individual specific substrate sequences from different regions of the tobacco mosaic virus (TMV) RNA. The cleavage efficiency and specificity of each unit-ribozymes in the tri-component ribozymes to its substrate was similar to its mono-ribozyme counterpart. When the three substrates were mixed and used as substrates for the tri-component ribozymes, only the activity of the unit-ribozymes RZ4 was clearly observed, the activities of the other two unit-ribozymes were greatly reduced. The reduction was mainly due to the fact that the two substrates BT2(+) and BT2(-) for RZ1 and RZ3 were complementary in sequence to each other and therefore formed duplex in the target region, thus must have strongly prevented the two ribozymes from forming the correct structures required for cleavage activity. In addition to its activity on the substrate BT2(+), the ribozyme RZ1 was found unexpectedly to be able to cleave BT4(-) specifically into various unique products.
Song
Ren-Tao
RT
State Key Laboratory of Plant Molecular Gentics, Shanghai Institute of Plant Physiology, the Chinese Academy of Sciences, Shanghai 200032, China.
Li
Jie
J
Jin
Hai-Ling
HL
Zhang
Qing-Qi
QQ
Xu
Zheng-Kai
ZK