Pace U, Szostak J W
Department of Molecular Biology, Massachusetts General Hospital, Boston 02114.
FEBS Lett. 1991 Mar 11;280(1):171-4. doi: 10.1016/0014-5793(91)80230-z.
The A-rich bulge in paired region P5a of the Tetrahymena intron is a structural feature that is conserved in the sub-group Ib self-splicing introns. We have constructed a series of substitution and deletion mutations in this region of the intron. Kinetic analysis has shown that some of the mutants have a reduced maximal extent of splicing, while others have a reduced Vmax. These mutations could be reactivated to a great extent by spermidine and high Mg2+ concentrations. These data are consistent with the hypothesis that the A-rich bulge of P5a has a role in stabilizing the higher-level structure of the ribozyme.
