Download MendeleyA conformational switch in PRP8 mediates metal ion coordination that promotes pre-mRNA exon ligation.
Schellenberg, M.J., Wu, T., Ritchie, D.B., Fica, S., Staley, J.P., Atta, K.A., Lapointe, P., Macmillan, A.M.(2013) Nat Struct Mol Biol 20: 728-734
- PubMed: 23686287
- DOI: https://doi.org/10.1038/nsmb.2556
- Primary Citation of Related Structures:
4JK7, 4JK8, 4JK9, 4JKA, 4JKB, 4JKC, 4JKD, 4JKE, 4JKF, 4JKG, 4JKH - PubMed Abstract:
Splicing of pre-mRNAs in eukaryotes is catalyzed by the spliceosome, a large RNA-protein metalloenzyme. The catalytic center of the spliceosome involves a structure comprising the U2 and U6 snRNAs and includes a metal bound by U6 snRNA. The precise architecture of the splicesome active site, however, and the question of whether it includes protein components, remains unresolved. A wealth of evidence places the protein PRP8 at the heart of the spliceosome through assembly and catalysis. Here we provide evidence that the RNase H domain of PRP8 undergoes a conformational switch between the two steps of splicing, rationalizing yeast prp8 alleles that promote either the first or second step. We also show that this switch unmasks a metal-binding site involved in the second step. Together, these data establish that PRP8 is a metalloprotein that promotes exon ligation within the spliceosome.
Organizational Affiliation:
Department of Biochemistry, University of Alberta, Edmonton, Alberta, Canada.
