The electrostatic character of the ribosomal surface enables extraordinarily rapid target location by ribotoxins

Alexei V. Korennykh, Joseph A. Piccirilli, Carl C. Correll

Research output: Contribution to journalArticle

49 Scopus citations

Abstract

α-sarcin ribotoxins comprise a unique family of ribonucleases that cripple the ribosome by catalyzing endoribonucleolytic cleavage of ribosomal RNA at a specific location in the sarcin/ricin loop (SRL). The SRL structure alone is cleaved site-specifically by the ribotoxin, but the ribosomal context enhances the reaction rate by several orders of magnitude. We show that, for the α-sarcin-like ribotoxin restrictocin, this catalytic advantage arises from favorable electrostatic interactions with the ribosome. Restrictocin binds at many sites on the ribosomal surface and under certain conditions cleaves the SRL with a second-order rate constant of 1.7 × 1010 M -1 s-1, a value that matches the predicted frequency of random restrictocin-ribosome encounters. The results suggest a mechanism of target location whereby restrictocin encounters ribosomes randomly and diffuses within the ribosomal electrostatic field to the SRL. These studies show a role for electrostatics in protein-ribosome recognition.

Original languageEnglish (US)
Pages (from-to)436-443
Number of pages8
JournalNature Structural and Molecular Biology
Volume13
Issue number5
DOIs
StatePublished - May 14 2006

All Science Journal Classification (ASJC) codes

  • Structural Biology
  • Molecular Biology

Fingerprint Dive into the research topics of 'The electrostatic character of the ribosomal surface enables extraordinarily rapid target location by ribotoxins'. Together they form a unique fingerprint.

  • Cite this