DNA wrapping in transcription initiation by RNA polymerase II

The DNA wrapping model of transcription stipulates that DNA bending and wra pping around RNA polymerase causes an unwinding of the DNA helix at the enz yme catalytic center that stimulates strand separation prior to initiation and during transcript elongation. Recent experiments with mammalian RNA pol ymerase II indicate the significance of DNA bending and wrapping in transcr iptional mechanisms. These findings have important implications in our unde rstanding of the role of the general transcription factors in transcription al initiation and the mechanisms underlying transcriptional regulation.