1. Academic Validation
  2. Crystal structure of human U1 snRNP, a small nuclear ribonucleoprotein particle, reveals the mechanism of 5' splice site recognition

Crystal structure of human U1 snRNP, a small nuclear ribonucleoprotein particle, reveals the mechanism of 5' splice site recognition

  • Elife. 2015 Jan 2;4:e04986. doi: 10.7554/eLife.04986.
Yasushi Kondo 1 Chris Oubridge 1 Anne-Marie M van Roon 1 Kiyoshi Nagai 1
Affiliations

Affiliation

  • 1 Structural Studies Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom.
Abstract

U1 snRNP binds to the 5' exon-intron junction of pre-mRNA and thus plays a crucial role at an early stage of pre-mRNA splicing. We present two crystal structures of engineered U1 sub-structures, which together reveal at atomic resolution an almost complete network of protein-protein and RNA-protein interactions within U1 snRNP, and show how the 5' splice site of pre-mRNA is recognised by U1 snRNP. The zinc-finger of U1-C interacts with the duplex between pre-mRNA and the 5'-end of U1 snRNA. The binding of the RNA duplex is stabilized by hydrogen bonds and electrostatic interactions between U1-C and the RNA backbone around the splice junction but U1-C makes no base-specific contacts with pre-mRNA. The structure, together with RNA binding assays, shows that the selection of 5'-splice site nucleotides by U1 snRNP is achieved predominantly through basepairing with U1 snRNA whilst U1-C fine-tunes relative affinities of mismatched 5'-splice sites.

Keywords

5′ splice site; U1 snRNP; biophysics; crystallography; human; pre-mRNA splicing; spliceosome; structural biology.

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