5xjc
From Proteopedia
Cryo-EM structure of the human spliceosome just prior to exon ligation at 3.6 angstrom
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 PubMedMechanistic understanding of pre-mRNA splicing requires detailed structural information on various states of the spliceosome. Here we report the cryo electron microscopy (cryo-EM) structure of the human spliceosome just before exon ligation (the C * complex) at an average resolution of 3.76 A. The splicing factor Prp17 stabilizes the active site conformation. The step II factor Slu7 adopts an extended conformation, binds Prp8 and Cwc22, and is poised for selection of the 3'-splice site. Remarkably, the intron lariat traverses through a positively charged central channel of RBM22; this unusual organization suggests mechanisms of intron recruitment, confinement, and release. The protein PRKRIP1 forms a 100-A alpha helix linking the distant U2 snRNP to the catalytic center. A 35-residue fragment of the ATPase/helicase Prp22 latches onto Prp8, and the quaternary exon junction complex (EJC) recognizes upstream 5'-exon sequences and associates with Cwc22 and the GTPase Snu114. These structural features reveal important mechanistic insights into exon ligation. An Atomic Structure of the Human Spliceosome.,Zhang X, Yan C, Hang J, Finci LI, Lei J, Shi Y Cell. 2017 May 18;169(5):918-929.e14. doi: 10.1016/j.cell.2017.04.033. Epub 2017 , May 11. PMID:28502770[5] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also
References
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Categories: Homo sapiens | Human adenovirus 2 | Large Structures | Finci IL | Hang J | Lei J | Shi Y | Yan C | Zhang X