Final answer:
Enhancers can affect the transcription of distant genes by bending the DNA to bring the enhancer near the promoter, where it increases transcription rates.
Step-by-step explanation:
An enhancer affects the transcription of distant genes by bending the DNA so that the enhancer can physically interact with the gene's promoter. While DNA is often depicted as a straight line, in reality, it is three-dimensional, and this allows distant enhancer regions to influence gene expression. Enhancers contain distal control elements that are binding sites for activator proteins.
Once these activators bind, they can interact with mediator proteins and transcription factors bound to a promoter, regardless of their respective positions along the DNA sequence. DNA bending proteins facilitate this process, forming loops in the DNA that bring these distant elements into close proximity, enabling the enhancer to increase the rate of transcription of its target gene.