SNAP output for PDB entry 6rbe [SNAP web server]

PDB-id

6rbe; SNAP-derived features in text and JSON formats; DNAproDB

Class

ribosome

Method

cryo-EM (3.8 Å)

Summary

State 2 of yeast tsr1-tap rps20-deltaloop pre-40s particles

Reference

Mitterer V, Shayan R, Ferreira-Cerca S, Murat G, Enne T, Rinaldi D, Weigl S, Omanic H, Gleizes PE, Kressler D, Plisson-Chastang C, Pertschy B (2019): "Conformational proofreading of distant 40S ribosomal subunit maturation events by a long-range communication mechanism." Nat Commun, 10, 2754. doi: 10.1038/s41467-019-10678-z.

Abstract

Eukaryotic ribosomes are synthesized in a hierarchical process driven by a plethora of assembly factors, but how maturation events at physically distant sites on pre-ribosomes are coordinated is poorly understood. Using functional analyses and cryo-EM, we show that ribosomal protein Rps20 orchestrates communication between two multi-step maturation events across the pre-40S subunit. Our study reveals that during pre-40S maturation, formation of essential contacts between Rps20 and Rps3 permits assembly factor Ltv1 to recruit the Hrr25 kinase, thereby promoting Ltv1 phosphorylation. In parallel, a deeply buried Rps20 loop reaches to the opposite pre-40S side, where it stimulates Rio2 ATPase activity. Both cascades converge to the final maturation steps releasing Rio2 and phosphorylated Ltv1. We propose that conformational proofreading exerted via Rps20 constitutes a checkpoint permitting assembly factor release and progression of pre-40S maturation only after completion of all earlier maturation steps.