Functional visualization of viral molecular motor by hydrogen-deuterium exchange reveals transient states

Jiří Lísal, TuKiet T. Lam, Denis E. Kainov, Mark Emmett, Alan G. Marshall, Roman Tuma

Research output: Contribution to journalArticle

51 Scopus citations

Abstract

Molecular motors undergo cyclical conformational changes and convert chemical energy into mechanical work. The conformational dynamics of a viral packaging motor, the hexameric helicase P4 of dsRNA bacteriophage φ8, was visualized by hydrogen-deuterium exchange and high-resolution mass spectrometry. Concerted changes of exchange kinetics revealed a cooperative unit that dynamically links ATP-binding sites and the central RNA-binding channel. The cooperative unit is compatible with a structure-based model in which translocation is mediated by a swiveling helix. Deuterium labeling also revealed the transition state associated with RNA loading, which proceeds via opening of the hexameric ring. The loading mechanism is similar to that of other hexameric helicases. Hydrogen-deuterium exchange provides an important link between time-resolved spectroscopic observations and high-resolution structural snapshots of molecular machines.

Original languageEnglish (US)
Pages (from-to)460-466
Number of pages7
JournalNature Structural and Molecular Biology
Volume12
Issue number5
DOIs
StatePublished - May 2005
Externally publishedYes

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ASJC Scopus subject areas

  • Structural Biology
  • Molecular Biology

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