Figure 6.7.Regulation of transcription. Thecis-acting elements are segments of DNA that regulate
transcription; these segments may be adjacent to the gene such as the promoter (CAAT box) and the
cis-acting gene-specific response elements, or they may be distant to the gene such as enhancers. The
trans-acting elements are transcription factors and other regulatory proteins that may associate with the
promoter, other proteins, or both.
Figure 6.8.Transcription factors structure and function. Transcription factors may have domains that
bindcis-acting elements such as enhancers, and domains that also bindtrans-acting elements such as
RNA polymerase (RNAP II) and other transcription factors.