Pol III transcription termination preferences on hairpin-encoding DNA coligos. (A) Coligo schematic with numbering at the 3′ end of the stem-larger loop junction to distinguish stem and loop positions. (B) Chart showing the frequency of Pol III transcription termination in relation to the stem-larger loop junction for all six coligos studied. (C) As in panel B, but only for the three coligos having a larger loop site resembling the canonical oligo dA Pol III termination sequence. (D) As in panel B, but for only the three coligos lacking a Pol III termination sequence. (E) Diagram illustrating the defining features of (right, green) the coligo initiator structure: a 5-nt stretch spanning the stem-larger loop junction, with preference for initiation at a pyrimidine (dC or dT) followed by a purine; and (left, red) the termination region: the 10 to 11 ss nt in the larger loop following the stem. (Tss) transcription start site.
