The DExD/H-box ATPase Prp2p destabilizes and proofreads the catalytic RNA core of the spliceosome

摘要: After undergoing massive RNA and protein rearrangements during assembly, the spliceosome undergoes a final, more subtle, ATP-dependent rearrangement that is essential for catalysis. This requires DEAH-box Prp2p, an RNA-dependent ATPase. Prp2p has been implicated in destabilizing interactions between complexes SF3 RES, but role RNA–RNA not explored. Using directed molecular genetics budding yeast, we have found cold-sensitive prp2 mutation suppressed only by mutations RES components also range of disrupt spliceosomal catalytic core element U2/U6 helix I, which juxtaposing 5′ splice site branch positioning metal ions catalysis within context putative triplex; indeed, this triplex mutation. Remarkably, rescue lethal I. These data provide evidence elements comprise are already formed at stage destabilizes these elements, directly or indirectly, both to proofread activation promote reconfiguration fully competent, conformation.