Figure 7.

Transcription factors and proteins of the histone core particle bend DNA duplex differently [49]. (Left) bending by transcription factors is acquired mostly by local adaptation to the A form (highlighted in red); shown is DNA from complex with TFIIB–Related Factor Brf2 (PDB id 4ROC [51]). (Right) bending by the histone core particle is associated with the BII form (highlighted in blue); shown are first 75 base pairs from a histone core particle (PDB id 5F99 [52]); when statistically measured over many structures, the BII form appears in histone-wrapped DNA every tenth step corresponding to one full turn of duplex; the periodicity of the BII form appearance explains the DNA bending.