Base pair recognition of the stereochemically [alpha]-substituted [gamma]-turn of pyrrole/imidazole hairpin polyamides

The recognition of the sequences 5'-NGCACA-3' (N = T, A, C, G) by pyrrole/imidazole polyamides with (R/S)-[alpha]-hydroxyl/[alpha]-amino-substituted [gamma]-aminobutyric acid as a [gamma]-turn is investigated. The results have indicated that [gamma]SO and [gamma]SN might function as T-recognition units at the turn position, as well as a [gamma]-turn in the discrimination of polyamides.