Primary Citation of Related Structures: 4YHU, 4YHV, 4YHW
PubMed Abstract:
Prp3 is an essential U4/U6 di-snRNP-associated protein whose functions and molecular mechanisms in pre-mRNA splicing are presently poorly understood. We show by structural and biochemical analyses that Prp3 contains a bipartite U4/U6 di-snRNA-binding region comprising an expanded ferredoxin-like fold, which recognizes a 3'-overhang of U6 snRNA, and a preceding peptide, which binds U4/U6 stem II ...
Prp3 is an essential U4/U6 di-snRNP-associated protein whose functions and molecular mechanisms in pre-mRNA splicing are presently poorly understood. We show by structural and biochemical analyses that Prp3 contains a bipartite U4/U6 di-snRNA-binding region comprising an expanded ferredoxin-like fold, which recognizes a 3'-overhang of U6 snRNA, and a preceding peptide, which binds U4/U6 stem II. Phylogenetic analyses revealed that the single-stranded RNA-binding domain is exclusively found in Prp3 orthologs, thus qualifying as a spliceosome-specific RNA interaction module. The composite double-stranded/single-stranded RNA-binding region assembles cooperatively with Snu13 and Prp31 on U4/U6 di-snRNAs and inhibits Brr2-mediated U4/U6 di-snRNA unwinding in vitro. RNP-disrupting mutations in Prp3 lead to U4/U6•U5 tri-snRNP assembly and splicing defects in vivo. Our results reveal how Prp3 acts as an important bridge between U4/U6 and U5 in the tri-snRNP and comparison with a Prp24-U6 snRNA recycling complex suggests how Prp3 may be involved in U4/U6 reassembly after splicing.
Related Citations:
Structure determination by multiple-wavelength anomalous dispersion (MAD) at the Pr LIII edge Pueringer, S., Hellmig, M., Liu, S., Weiss, M., Wahl, M.C., Mueller, U. (2012) Acta Crystallogr Sect F Struct Biol Cryst Commun 68: 981
Organizational Affiliation:
Laboratory of Structural Biochemistry, Freie Universität Berlin, Berlin, Germany.
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