CryoEM structures of spliceosomal complexes reveal the molecular mechanism of pre-mRNA splicing. (October 2017)

• Record Type: Journal Article
• Authors: Scheres, Sjors HW; Nagai, Kiyoshi
• Is Part Of: Current opinion in structural biology. Volume 46(2017)
• Page Start: 130
• Page End: 139
• Publication Date: 2017-10
• Subjects: Molecular biology -- Periodicals; 570
• DOI: 10.1016/j.sbi.2017.08.001
• Languages: English
• ISSNs: 0959-440X

Abstract

Highlights: The spliceosome structures revealed in different states at near atomic resolution. Introns are excised from mRNA precursors by two trans-esterification reactions. The spliceosome is a ribozyme and uses a single active site for the two reactions. The active site forms after the fully assembled spliceosome undergoes remodelling. RNA helicases regulate docking of the substrates and undocking of the products. Abstract : The spliceosome is an intricate molecular machine which catalyses the removal of introns from eukaryotic mRNA precursors by two trans-esterification reactions (branching and exon ligation) to produce mature mRNA with uninterrupted protein coding sequences. The structures of the spliceosome in several key states determined by electron cryo-microscopy have greatly advanced our understanding of its molecular mechanism. The catalytic RNA core is formed during the activation of the fully assembled B to Bact complex and remains largely unchanged throughout the splicing cycle. RNA helicases and step specific factors regulate docking and undocking of the substrates (branch site and 3′ splice site) to the single RNA-based active site to catalyse the two trans-esterification reactions.