Affinity and specificity of multiple hydroxypyrrole/pyrrole ring pairings for coded recognition of DNA

Three consecutive amino acid ring Hp/Py pairs can be combined in a hairpin model to specify core sequence 5'-TTA-3' from 5'-TAT-3' in the DNA minor groove. These ring pairs were used in identifying sequences in the minor groove of the DNA. Experiments found that hydroxypyrrole-imidazole-pyrrole polyamides complete the design of the minor groove recognition code. The four-ring pairs Im/Py, Py/Im, Hp/Py and Py/Hp complete the code and complement four Watson-Crick base pairs.