The guanosine binding mechanism of the Tetrahymena group I intron. |
| |
| Authors: | A Kitamura Y Muto S Watanabe I Kim T Ito Y Nishiya T Ohtsuki G Kawai K Watanabe K Hosono H Takaku E Katoh T Yamazaki T Inoue S Yokoyama |
| |
| Affiliation: | Department of Biophysics and Biochemistry, Graduate School of Science, University of Tokyo, Japan. |
| |
| Abstract: | The Tetrahymena group I intron catalyzes self-splicing through two consecutive transesterification reactions, using a single guanosine-binding site (GBS). In this study, we constructed a model RNA that contains the GBS and a conserved guanosine nucleotide at the 3'-terminus of the intron (omegaG). We determined by NMR the solution structure of this model RNA, and revealed the guanosine binding mechanism of the group I intron. The G22 residue, corresponding to omegaG, participates in a base triple, G22 xx G3 x C12, hydrogen-bonding to the major groove edge of the Watson-Crick G3 x C12 pair. The G22 residue also interacts with A2, which is semi-conserved in all sequenced group I introns. |
| |
| Keywords: | |
|
|
