6id0
From Proteopedia
Cryo-EM structure of a human intron lariat spliceosome prior to Prp43 loaded (ILS1 complex) at 2.9 angstrom resolution
Structural highlights
DiseasePRP8_HUMAN Defects in PRPF8 are the cause of retinitis pigmentosa type 13 (RP13) [MIM:600059. RP leads to degeneration of retinal photoreceptor cells. Patients typically have night vision blindness and loss of midperipheral visual field. As their condition progresses, they lose their far peripheral visual field and eventually central vision as well. RP13 inheritance is autosomal dominant.[1] [2] [:][3] [4] FunctionPRP8_HUMAN Central component of the spliceosome, which may play a role in aligning the pre-mRNA 5'- and 3'-exons for ligation. Interacts with U5 snRNA, and with pre-mRNA 5'-splice sites in B spliceosomes and 3'-splice sites in C spliceosomes. Publication Abstract from PubMedPre-mRNA splicing is executed by the spliceosome, which has eight major functional states each with distinct composition. Five of these eight human spliceosomal complexes, all preceding exon ligation, have been structurally characterized. In this study, we report the cryo-electron microscopy structures of the human post-catalytic spliceosome (P complex) and intron lariat spliceosome (ILS) at average resolutions of 3.0 and 2.9 A, respectively. In the P complex, the ligated exon remains anchored to loop I of U5 small nuclear RNA, and the 3'-splice site is recognized by the junction between the 5'-splice site and the branch point sequence. The ATPase/helicase Prp22, along with the ligated exon and eight other proteins, are dissociated in the P-to-ILS transition. Intriguingly, the ILS complex exists in two distinct conformations, one with the ATPase/helicase Prp43 and one without. Comparison of these three late-stage human spliceosomes reveals mechanistic insights into exon release and spliceosome disassembly. Structures of the human spliceosomes before and after release of the ligated exon.,Zhang X, Zhan X, Yan C, Zhang W, Liu D, Lei J, Shi Y Cell Res. 2019 Feb 6. pii: 10.1038/s41422-019-0143-x. doi:, 10.1038/s41422-019-0143-x. PMID:30728453[5] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also
References
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Categories: Homo sapiens | Large Structures | Shi Y | Yan C | Zhan X | Zhang X