Site-specific fluorescence dynamics in an RNA 'thermometer' reveals the role of ribosome binding in its temperature-sensitive switch function.

ABSTRACT: RNA thermometers control the translation of several heat shock and virulence genes by their temperature-sensitive structural transitions. Changes in the structure and dynamics of MiniROSE RNA, which regulates translation in the temperature range of 20-45°C, were studied by site specifically replacing seven adenine residues with the fluorescent analog, 2-aminopurine (2-AP), one at a time. Dynamic fluorescence observables of 2-AP-labeled RNAs were compared in their free versus ribosome-bound states for the first time. Noticeably, position dependence of fluorescence observables, which was prominent at 20°C, was persistent even at 45ºC, suggesting the persistence of structural integrity up to 45ºC. Interestingly, position-dependent dispersion of fluorescence lifetime and quenching constant at

SUBMITTER: Narayan S 

PROVIDER: S-EPMC4288164 | biostudies-literature | 2015 Jan

REPOSITORIES: biostudies-literature