| Structural highlights
Function
CWC21_YEAST Involved in pre-mRNA splicing. May function at or prior to the first catalytic step of splicing at the catalytic center of the spliceosome, together with ISY1. May do so by stabilizing the catalytic center or the position of the RNA substrate.[1] [2]
Publication Abstract from PubMed
Each cycle of pre-messenger RNA splicing, carried out by the spliceosome, comprises two sequential transesterification reactions, which result in the removal of an intron and the joining of two exons. Here we report an atomic structure of a catalytic step I spliceosome (known as the C complex) from Saccharomyces cerevisiae, as determined by cryo-electron microscopy at an average resolution of 3.4 angstroms. In the structure, the 2'-OH of the invariant adenine nucleotide in the branch point sequence (BPS) is covalently joined to the phosphate at the 5' end of the 5' splice site (5'SS), forming an intron lariat. The freed 5' exon remains anchored to loop I of U5 small nuclear RNA (snRNA), and the 5'SS and BPS of the intron form duplexes with conserved U6 and U2 snRNA sequences, respectively. Specific placement of these RNA elements at the catalytic cavity of Prp8 is stabilized by 15 protein components, including Snu114 and the splicing factors Cwc21, Cwc22, Cwc25, and Yju2. These features, representing the conformation of the spliceosome after the first-step reaction, predict structural changes that are needed for the execution of the second-step transesterification reaction.
Structure of a yeast catalytic step I spliceosome at 3.4 A resolution.,Wan R, Yan C, Bai R, Huang G, Shi Y Science. 2016 Aug 26;353(6302):895-904. doi: 10.1126/science.aag2235. Epub 2016, Jul 21. PMID:27445308[3]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Khanna M, Van Bakel H, Tang X, Calarco JA, Babak T, Guo G, Emili A, Greenblatt JF, Hughes TR, Krogan NJ, Blencowe BJ. A systematic characterization of Cwc21, the yeast ortholog of the human spliceosomal protein SRm300. RNA. 2009 Dec;15(12):2174-85. Epub 2009 Sep 29. PMID:19789211 doi:http://dx.doi.org/rna.1790509
- ↑ Grainger RJ, Barrass JD, Jacquier A, Rain JC, Beggs JD. Physical and genetic interactions of yeast Cwc21p, an ortholog of human SRm300/SRRM2, suggest a role at the catalytic center of the spliceosome. RNA. 2009 Dec;15(12):2161-73. Epub 2009 Oct 23. PMID:19854871 doi:http://dx.doi.org/rna.1908309
- ↑ Wan R, Yan C, Bai R, Huang G, Shi Y. Structure of a yeast catalytic step I spliceosome at 3.4 A resolution. Science. 2016 Aug 26;353(6302):895-904. doi: 10.1126/science.aag2235. Epub 2016, Jul 21. PMID:27445308 doi:http://dx.doi.org/10.1126/science.aag2235
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