Insight into the structural organization of the omega leader of TMV RNA: The role of various regions of the sequence in the formation of a compact structure of the omega RNA

► Polyribonucleotides containing altered omega sequences of TMV RNA are synthesized. ► Synthetic RNAs are studied by sedimentation and thermal melting technique. ► The modified RNAs are less stable and less compact than the original omega RNA. ► Central (CAA)n and 3′-end parts form together stable tertiary structure of omega RNA.