The spliceosome consists of five RNAs and more than 100 associated proteins. One of these, PRP8, is both one of the largest and most highly conserved spliceosomal proteins. Previous genetic and cross-linking data pointed to the importance of ___domain IV of PRP8 in spliceosome assembly and/or catalysis. Its structure has now been solved and found to contain an RNase H fold, suggestive of an RNA binding surface. The RNA binding data suggest that the PRP8 core recognizes, rather than a specific sequence, a structure resembling the four-helix junction proposed for the catalytically active U2/U6 snRNA interaction.
- Dustin B Ritchie
- Matthew J Schellenberg
- Andrew M MacMillan