RT Journal Article
SR Electronic
T1 The structure of yeast Npl3 bound to RNA reveals a cooperative sequence-specific recognition and an RNA chaperone role in splicing
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2022.05.24.493251
DO 10.1101/2022.05.24.493251
A1 Ahmed Moursy
A1 Antoine Cléry
A1 Stefan Gerhardy
A1 Katharina M. Betz
A1 Sanjana Rao
A1 Sébastien Campagne
A1 Irene Beusch
A1 Malgorzata M. Duszczyk
A1 Mark D. Robinson
A1 Vikram Govind Panse
A1 Frédéric H.-T. Allain
YR 2022
UL http://biorxiv.org/content/early/2022/05/25/2022.05.24.493251.abstract
AB The conserved SR-like protein Npl3 promotes splicing of diverse pre-mRNAs. However, the RNA sequence(s) recognized by the RNA Recognition Motifs (RRM1 & RRM2) of Npl3 during the splicing reaction remain elusive. Here, we developed a split-iCRAC approach in yeast to uncover the consensus sequence bound to each RRM. High-resolution NMR structures show that RRM2 recognizes a 5’-GNGG-3’ motif leading to an unusual mille-feuille topology. These structures also reveal how RRM1 preferentially interacts with a CC-dinucleotide upstream of this motif, and how the inter-RRM linker and the region C-terminal to RRM2 contributes to cooperative RNA-binding. Structure-guided functional studies show that Npl3 genetically interacts with U2 snRNP specific factors and we provide evidence that Npl3 melts U2 snRNA stem-loop I, a prerequisite for U2/U6 duplex formation within the catalytic center of the Bact spliceosomal complex. Thus, our findings provide insights into an unanticipated RNA chaperoning role for Npl3 during spliceosome active site formation.Competing Interest StatementThe authors have declared no competing interest.