A wobble pair, or wobble base pair, is a hydrogen-bonded pairing between two nucleotides generally occurring between two RNA molecules. These base pairs are geometrically distinct from the canonical Watson-Crick-type base-pairing. The main wobble base pairs are hypoxanthine-uracil (I-U, where I represents inosine, the nucleoside formed from hypoxanthine), guanine-uracil (G-U), hypoxanthine-adenine (I-A), and hypoxanthine-cytosine (I-C). Wobble base pairs are of comparable thermodynamic stability to Watson-Crick base pairs. Wobble base pairs occur frequently in RNA secondary structure and are important for proper translation of the genetic code.
In 1966, Francis Crick proposed the Wobble hypothesis to account for the fact that most organisms do not seem to have as many tRNA molecules as would be required for complete translation of the genetic code. There are 64 possible codons in the genetic code. During translation, each of these codons requires a tRNA molecule with a...