RNA chaperones buffer deleterious mutations in E. coli

‘RNA chaperones buffer deleterious mutations in E. coli’
MedILS scientists Marina Rudan and Anita Krisko (Basic Biology of Aging Laboratory, MedILS, Split, Croatia) in collaboration with Dominique Schneider (Laboratoire Adaptation et Pathogénie des Microorganismes, Université Grenoble Alpes, Grenoble, France) and Tobias Warnecke (Molecular Systems Group, MRC Clinical Sciences Centre, Imperial College, London, United Kingdom), published an article in in the highly prestigious eLife journal.
Both proteins and RNAs can misfold into non-functional conformations. Protein chaperones promote native folding of nascent polypeptides and re-folding of misfolded species, thereby buffering mutations that compromise protein structure and function. Here they show that RNA chaperones can also act as mutation buffers that enhance organismal fitness. Using competition assays, they demonstrate that overexpression of select RNA chaperones, including three DEAD box RNA helicases (CsdA, SrmB, RhlB) and the cold shock protein CspA, improves fitness of two independently evolved E. coli mutator strains that have accumulated deleterious mutations during short- and long-term laboratory evolution. They identify strain-specific mutations that are deleterious and subject to buffering when introduced individually into the ancestral genotype. For DEAD box RNA helicases they show that buffering requires helicase activity, implicating RNA structural remodelling in the buffering process. Their results suggest that RNA chaperones might play a fundamental role in RNA evolution and evolvability.
Full article you could find on: