Non-Watson-Crick base pair associations contribute significantly to the stabilization of RNA tertiary structure. The conformation adopted by such pairs appears to be a mbt uk function of both mbt shoes clearance uk the sequence and the secondary structure of the RNA molecule. G.A mispairs adopt G .
A configurations in some circumstances, such as the ends of helical regions of rRNAs, but in other circumstances probably adopt mbt shoes reviews an unusual configuration in which the inter-base hydrogen bonds involve functional groups from other bases. We investigated mbt shoes john lewis uk the structure of G.A pairs in a synthetic RNA dodecamer, which forms a duplex containing two such mismatches.The structure of the RNA duplex was determined by single crystal X-ray diffraction techniques to a resolution in the range 7.0-1.8A, and… found to be an A-type helical structure with 10 Watson-Crick pairs and two G.A mispairs. The mispairs adopt the G.A conformation, held together by two obvious hydrogen bonds. Unlike analogous base pairs seen in a DNA duplex, they do not exhibit a high propeller twist and may therefore be further stabilized by weak, reverse, three-center hydrogen bonds G.
A mispairs are held together by two hydrogen of guanine and the N6 and N1 of adenine. If the mispairs do not exhibit high propeller mbt shop london twist they mbt chapa may be further stabilized by inter-base reverse three-centre hydrogen bonds. These interactions, and other hydrogen bonds seen in our study, may be important in modelling the structure of RNA molecules and their interactions with other molecules.