Optimal molecular crowding accelerates group II intron folding and maximizes catalysis.

ABSTRACT: Unlike in vivo conditions, group II intron ribozymes are known to require high magnesium(II) concentrations ([Mg²⁺]) and high temperatures (42 °C) for folding and catalysis in vitro. A possible explanation for this difference is the highly crowded cellular environment, which can be mimicked in vitro by macromolecular crowding agents. Here, we combined bulk activity assays and single-molecule Förster Resonance Energy Transfer (smFRET) to study the influence of polyethylene glycol (PEG) on catalysis and folding of the ribozyme. Our activity studies reveal that PEG reduces the [Mg²⁺] required, and we found an "optimum" [PEG] that yields maximum activity. smFRET experiments show that the most compact state population, the putative active state, increases with increasing [

SUBMITTER: Paudel BP 

PROVIDER: S-EPMC6255197 | biostudies-literature | 2018 Nov

REPOSITORIES: biostudies-literature