RNA structural rearrangement via unwinding and annealing by the cyanobacterial RNA helicase, CrhR

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dc.contributor.authorOwttrim, George W.
dc.contributor.authorChamot, Danuta
dc.contributor.authorKujat-Choy, Sonya L.
dc.contributor.authorColvin, Kimberley R.
dc.date.accessioned2025-05-01T12:00:20Z
dc.date.available2025-05-01T12:00:20Z
dc.date.issued2005
dc.descriptionRearrangement of RNA secondary structure is crucial for numerous biological processes. RNA helicases participate in these rearrangements through the unwinding of duplex RNA. We report here that the redox-regulated cyanobacterial RNA helicase, CrhR, is a bona fide RNA helicase possessing both RNA-stimulated ATPase and bidirectional ATP-stimulated RNA helicase activity. The processivity of the unwinding reaction appears to be low, because RNA substrates containing duplex regions of 41 bp are not unwound. CrhR also catalyzes the annealing of complementary RNA into intermolecular duplexes. Uniquely and in contrast to other proteins that perform annealing, the CrhR-catalyzed reactions require ATP hydrolysis. Through a combination of the unwinding and annealing activities, CrhR also catalyzes RNA strand exchange resulting in the formation of RNA secondary structures that are too stable to be resolved by helicase activity. RNA strand exchange most probably occurs through the CrhR-dependent formation and resolution of an RNA branch migration structure. Demonstration that another cyanobacterial RNA helicase, CrhC, does not catalyze annealing indicates that this activity is not a general biochemical characteristic of RNA helicases. Biochemically, CrhR resembles RecA and related proteins that catalyze strand exchange and branch migration on DNA substrates, a characteristic that is reflected in the recently reported structural similarities between these proteins. The data indicate the potential for CrhR to catalyze dynamic RNA secondary structure rearrangements through a combination of RNA helicase and annealing activities.
dc.identifier.doihttps://doi.org/10.7939/R3P84496X
dc.language.isoen
dc.relationhttp://doi.org/10.1074/jbc.M409700200
dc.relation.isversionofChamot, Danuta, Colvin, Kimberley R., Kujat-Choy, Sonya L., & Owttrim, George W. (2005). RNA structural rearrangement via unwinding and annealing by the cyanobacterial RNA helicase, CrhR. Journal of Biological Chemistry, 280(3), 2036-2044. http://doi.org/10.1074/jbc.M409700200
dc.rights© 2005 Danuta Chamot et al. This version of this article is open access and can be downloaded and shared. The original author(s) and source must be cited.
dc.subjectBranch Migration
dc.subjectTranslation Initiation
dc.subjectDead-Box Proteins
dc.subjectSaccharomyces-Cerevisiae
dc.subjectDbpa
dc.subjectMacromolecular Machines
dc.subjectAtp Hydrolysis
dc.subjectIn-Vivo; P68; Reduction
dc.titleRNA structural rearrangement via unwinding and annealing by the cyanobacterial RNA helicase, CrhR
dc.typehttp://purl.org/coar/resource_type/c_6501 http://purl.org/coar/version/c_970fb48d4fbd8a85
ual.jupiterAccesshttp://terms.library.ualberta.ca/public

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