Structural highlights
Function
PRP8_YEAST Required for pre-spliceosome formation, which is the first step of pre-mRNA splicing. This protein is associated with snRNP U5. Has a role in branch site-3' splice site selection. Associates with the branch site-3' splice 3'-exon region. Also has a role in cell cycle.[1] [2] [3] [4]
Publication Abstract from PubMed
Yeast U5 small nuclear ribonucleoprotein particle (snRNP) is assembled via a cytoplasmic precursor that contains the U5-specific Prp8 protein but lacks the U5-specific Brr2 helicase. Instead, pre-U5 snRNP includes the Aar2 protein not found in mature U5 snRNP or spliceosomes. Aar2p and Brr2p bind competitively to a C-terminal region of Prp8p that comprises consecutive RNase H-like and Jab1/MPN-like domains. To elucidate the molecular basis for this competition, we determined the crystal structure of Aar2p in complex with the Prp8p RNase H and Jab1/MPN domains. Aar2p binds on one side of the RNase H domain and extends its C terminus to the other side, where the Jab1/MPN domain is docked onto a composite Aar2p-RNase H platform. Known Brr2p interaction sites of the Jab1/MPN domain remain available, suggesting that Aar2p-mediated compaction of the Prp8p domains sterically interferes with Brr2p binding. Moreover, Aar2p occupies known RNA-binding sites of the RNase H domain, and Aar2p interferes with binding of U4/U6 di-snRNA to the Prp8p C-terminal region. Structural and functional analyses of phospho-mimetic mutations reveal how phosphorylation reduces affinity of Aar2p for Prp8p and allows Brr2p and U4/U6 binding. Our results show how Aar2p regulates both protein and RNA binding to Prp8p during U5 snRNP assembly.
Structural basis for dual roles of Aar2p in U5 snRNP assembly.,Weber G, Cristao VF, Santos KF, Jovin SM, Heroven AC, Holton N, Luhrmann R, Beggs JD, Wahl MC Genes Dev. 2013 Mar 1;27(5):525-40. doi: 10.1101/gad.213207.113. Epub 2013 Feb, 26. PMID:23442228[5]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Jackson SP, Lossky M, Beggs JD. Cloning of the RNA8 gene of Saccharomyces cerevisiae, detection of the RNA8 protein, and demonstration that it is essential for nuclear pre-mRNA splicing. Mol Cell Biol. 1988 Mar;8(3):1067-75. PMID:2835658
- ↑ Abovich N, Rosbash M. Cross-intron bridging interactions in the yeast commitment complex are conserved in mammals. Cell. 1997 May 2;89(3):403-12. PMID:9150140
- ↑ McPheeters DS, Muhlenkamp P. Spatial organization of protein-RNA interactions in the branch site-3' splice site region during pre-mRNA splicing in yeast. Mol Cell Biol. 2003 Jun;23(12):4174-86. PMID:12773561
- ↑ Yang K, Zhang L, Xu T, Heroux A, Zhao R. Crystal structure of the beta-finger domain of Prp8 reveals analogy to ribosomal proteins. Proc Natl Acad Sci U S A. 2008 Sep 16;105(37):13817-22. Epub 2008 Sep 8. PMID:18779563
- ↑ Weber G, Cristao VF, Santos KF, Jovin SM, Heroven AC, Holton N, Luhrmann R, Beggs JD, Wahl MC. Structural basis for dual roles of Aar2p in U5 snRNP assembly. Genes Dev. 2013 Mar 1;27(5):525-40. doi: 10.1101/gad.213207.113. Epub 2013 Feb, 26. PMID:23442228 doi:10.1101/gad.213207.113
