Use of Chemical Modification To Elucidate RNA Folding Pathways

As discussed in this overview, chemical modification is sensitive to the accessibility of a nucleotide to the solvent, and many nucleotides become less accessible as an RNA folds into its structured form. Chemical modification reagents are therefore suitable for following RNA folding, and can be used to study the kinetics of structure formation on time scales ranging from minutes to hours.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/143596/1/cpnc1109.pd

Micromechanics of Single Supercoiled DNA Molecules

Abstract. The theory of the mechanical response of single DNA molecules un-der stretching and twisting stresses is reviewed. Using established results for the the semiflexible polymer including the effect of torsional stress, and for the free energy of plectonemic supercoils, a theory of coexisting plectonemic and extended DNA is con-structed and shown to produce phenomena observed experimentally. Analytical results for DNA extension and torque are presented, and effects of anharmonicities in the plec-tonemic free energy are described. An application of the theory to the problem of torsional-stress-induced cruciform extrusion is also discussed. Key words. DNA, molecular biology, statistical mechanics, polymer physics. AMS(MOS) subject classifications. 82D60, 92C05, 92C40