CHARACTERIZATION OF THE NEWLY CONSTRUCTED DOMAINS THAT REPLACE P5ABC WITHIN THE TETRAHYMENA RIBOZYME

The P5abc domain of the Tetrahymena ribozyme has been shown to functio n as an activator that enhances core catalytic activity of the ribozym e. We reported previously that several new domains in that their prima ry sequences are different from that of P5abc are also capable of acti vating the ribozyme. It was unclear whether the mechanism of activatio n by the new domains is identical to that by P5abc. We have investigat ed structural and functional properties of the new domains and obtaine d evidence that strongly indicates that a particular domain activates the ribozyme in a different manner from that by P5abc.