Conformational proofreading of distant 40S ribosomal subunit maturation events by a long-range communication mechanism.Mitterer, V., Shayan, R., Ferreira-Cerca, S., Murat, G., Enne, T., Rinaldi, D., Weigl, S., Omanic, H., Gleizes, P.E., Kressler, D., Plisson-Chastang, C., Pertschy, B.
(2019) Nat Commun 10: 2754-2754
- PubMed: 31227701
- DOI: https://doi.org/10.1038/s41467-019-10678-z
- Primary Citation of Related Structures:
- PubMed 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.
Biochemistry III - Institute for Biochemistry, Genetics and Microbiology, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany. firstname.lastname@example.org.