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Publication Abstract from PubMed

We describe the structure in aqueous solution of a DNA duplex containing a base pair that is structurally analogous to A-T but which lacks hydrogen bonds. Base analogues F (a nonpolar isostere of thymine) and Z (a nonpolar isostere of adenine) are paired opposite one another in a 12 base pair duplex. The sequence context is the binding site of recently studied transcription factor hSRY. The Z-F pair has been shown to be replicated surprisingly well and selectively by DNA polymerase enzymes, considering that it is destabilizing and lacks Watson-Crick hydrogen bonds. The enzymatic studies led to the suggestion that part of the functional activity arises because the pair resembles a natural one in geometry. The present results show that, despite the absence of Watson-Crick hydrogen bonds, the Z-F pair structurally resembles an A-T pair in the same context. This lends support to the proposal that shape matching is an important component in replication, and suggests the general utility of using Z-F as a nonpolar replacement for A-T in probing protein-DNA interactions.

Solution Structure of a Nonpolar, Non-Hydrogen-Bonded Base Pair Surrogate in DNA.,Guckian KM, Krugh TR, Kool ET J Am Chem Soc. 2000 Jul 26;122(29):6841-6847. doi: 10.1021/ja994164v. PMID:20882115^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.