LAUSR

Significance Transcription at the enhancer and target promoter is highly coordinated, but it is unclear why. Using unique cell-free assays, here we were able to demonstrate that transcription at the enhancer and target promoter is interdependent, which relies on the physical availability of both the enhancer and the promoter, on the act of transcription at both the enhancer and promoter, on the abundance of transcripts from both the enhancer and promoter, and on direct enhancer–promoter contacts. We argue with supporting evidence that such interdependence and regulatory specificity can be explained if the enhancer and the promoter are entangled within a transcriptional bubble that both provides shared resources for transcription and is regulatable by the transcript levels generated.