Repetitive RNA unwinding by RNA helicase A facilitates RNA annealing.

ABSTRACT: Helicases contribute to diverse biological processes including replication, transcription and translation. Recent reports suggest that unwinding of some helicases display repetitive activity, yet the functional role of the repetitiveness requires further investigation. Using single-molecule fluorescence assays, we elucidated a unique unwinding mechanism of RNA helicase A (RHA) that entails discrete substeps consisting of binding, activation, unwinding, stalling and reactivation stages. This multi-step process is repeated many times by a single RHA molecule without dissociation, resulting in repetitive unwinding/rewinding cycles. Our kinetic and mutational analysis indicates that the two double stand RNA binding domains at the N-terminus of RHA are responsible for such repetitive unwinding

SUBMITTER: Koh HR 

PROVIDER: S-EPMC4117756 | biostudies-literature | 2014 Jul

REPOSITORIES: biostudies-literature