The G·U wobble base pair.

The G˙U wobble base pair is a fundamental unit of RNA secondary structure that is present in nearly every class of RNA from organisms of all three phylogenetic domains. It has comparable thermodynamic stability to Watson-Crick base pairs and is nearly isomorphic to them. Therefore, it often substitutes for G˙C or A˙U base pairs. The G˙U wobble base pair also has unique chemical, structural, dynamic and ligand- binding properties, which can only be partially mimicked by Watson-Crick base pairs or other mispairs. These features mark sites containing G˙U pairs for recognition by proteins and other RNAS and allow the wobble pair to play essential functional roles in a remarkably wide range of biological processes. [ABSTRACT FROM AUTHOR]