Abstract
Naturally occurring RNAs can display either long double-helical structures, as in viral dsRNA, or a globular structure with short double-helical domains connected by single-stranded stretches (Saenger, 1984). Globular RNAs are involved in transcription and translation, and form important components of ribosomes, spliceosomes, ribozymes, and several viruses. Reliable prediction of the three-dimensional structures of RNA chains in these molecular structures can give important insights into their functional behaviour.