SNAP output for PDB entry 1a9n [SNAP web server]

PDB-id

1a9n; SNAP-derived features in text and JSON formats; DNAproDB

Class

RNA binding protein-RNA

Method

X-ray (2.38 Å)

Summary

Crystal structure of the spliceosomal u2b''-u2a' protein complex bound to a fragment of u2 small nuclear RNA

Reference

Price SR, Evans PR, Nagai K (1998): "Crystal structure of the spliceosomal U2B"-U2A' protein complex bound to a fragment of U2 small nuclear RNA." Nature, 394, 645-650. doi: 10.1038/29234.

Abstract

We have determined the crystal structure at 2.4 A resolution of a ternary complex between the spliceosomal U2B"/U2A' protein complex and hairpin-loop IV of U2 small nuclear RNA. Unlike its close homologue the U1A protein, U2B" binds to its cognate RNA only in the presence of U2A', which contains leucine-rich repeats in its sequence. The concave surface of a parallel beta-sheet within the leucine-rich-repeat region of U2A' interacts with the ribonucleoprotein domain of U2B" on the surface opposite its RNA-binding surface. The basic carboxy-terminal region of U2A' interacts with the RNA stem. The crystal structure reveals how protein-protein interaction regulates RNA-binding specificity, and how replacing only a few key residues allows the U2B" and U1A proteins to discriminate between their cognate RNA hairpins by forming alternative networks of interactions.