3-DIMENSIONAL MODEL FOR SLIPPED LOOP RNA

Earlier a three-dimensional model for a new unusual DNA conformation r eferred to as Slipped Loop Structure (SLS) has been suggested by us (1 ). The same type of folding could occur with RNA as well which means t hat one must use the A-form of the double helix rather than the B-one. The present paper discusses the creation of an all-atom stereochemica lly sound model for SLS-RNA. This calculated model, while possessing t he same folding topology as the SLS-DNA, differs dramatically from the SLS-DNA by an overall folding geometry. It also differs radically fro m the RNA-pseudoknot and can thus be regarded as a new type of an RNA folding.