6teo

Publication Abstract from PubMed

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.

A Snu114-GTP-Prp8 module forms a relay station for efficient splicing in yeast.,Jia J, Ganichkin OM, Preussner M, Absmeier E, Alings C, Loll B, Heyd F, Wahl MC Nucleic Acids Res. 2020 Mar 20. pii: 5810484. doi: 10.1093/nar/gkaa182. PMID:32196113^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.