Download MendeleyA Snu114-GTP-Prp8 module forms a relay station for efficient splicing in yeast.
Jia, J., Ganichkin, O.M., Preussner, M., Absmeier, E., Alings, C., Loll, B., Heyd, F., Wahl, M.C.(2020) Nucleic Acids Res 48: 4572-4584
- PubMed: 32196113
- DOI: https://doi.org/10.1093/nar/gkaa182
- Primary Citation of Related Structures:
6TEO - PubMed Abstract:
The single G protein of the spliceosome, Snu114, has been proposed to facilitate splicing as a molecular motor or as a regulatory G protein. However, available structures of spliceosomal complexes show Snu114 in the same GTP-bound state, and presently no Snu114 GTPase-regulatory protein is known. We determined a crystal structure of Snu114 with a Snu114-binding region of the Prp8 protein, in which Snu114 again adopts the same GTP-bound conformation seen in spliceosomes. Snu114 and the Snu114-Prp8 complex co-purified with endogenous GTP. Snu114 exhibited weak, intrinsic GTPase activity that was abolished by the Prp8 Snu114-binding region. Exchange of GTP-contacting residues in Snu114, or of Prp8 residues lining the Snu114 GTP-binding pocket, led to temperature-sensitive yeast growth and affected the same set of splicing events in vivo. Consistent with dynamic Snu114-mediated protein interactions during splicing, our results suggest that the Snu114-GTP-Prp8 module serves as a relay station during spliceosome activation and disassembly, but that GTPase activity may be dispensable for splicing.
Organizational Affiliation:
Freie Universität Berlin, Laboratory of Structural Biochemistry, Takustraβe 6, D-14195 Berlin, Germany.
