| Popis: |
Through a novel "polymerase-stall" labeling procedure, we have successfully generated torsionally constrained molecules of double-stranded RNA (dsRNA). We have anchored these molecules within a magnetic tweezers apparatus, and by rotating the magnets, induced both positive and negative supercoils within these molecules. Up to this point, only experimental data from supercoiling dsDNA has been available for testing current models of the elastic behavior of twist-storing polymers. Since dsRNA is an A-helix (whereas dsDNA is a B-helix), it has differing values for both bending and twisting stiffness, and thus provides a valuable second-case for the testing and refinement of these models.Furthermore, dsRNA has important roles within biology, in its own right; not least among these, is that dsRNA is the central player in the gene-silencing pathway mediated through small interfering RNAs (siRNAs). The novel dsRNA substrates we have created, now pave the way for a more detailed understanding of the mechanistic action of the processes that constitute this pathway, at the single-molecule level. |
