Determination of in vivo target search kinetics of regulatory noncoding RNA

Abstract

RNA kinetics may define regulatory hierarchy The double-helical structure of DNA suggests immediately how nucleic acid polymers can recognize and bind to homologous sequences. Target recognition by RNA is vital in many biological processes. Fei et al. used super-resolution microscopy of tagged RNAs and computer modeling to understand how RNA-RNA base-pairing reactions occur in vivo. They studied a small RNA (sRNA) that targets a messenger RNA (mRNA) for degradation in bacteria. They observed a slow rate of association as the sRNA searched for its mRNA target, but thereafter a fast rate of dissociation. This explains the need for high concentrations of sRNA to cause mRNA degradation. The sRNA found different target mRNAs at different rates, allowing the generation of a regulatory hierarchy. Science , this issue p. 1371