Human genetics provides clues to why DNA regulatory regions get 'loopy'

DNA transcription is the vital first step needed for switching on our genes. For a gene to be switched on, it must be acted upon by an enzyme called RNA polymerase. This is a molecular machine which can read DNA and create a matching strand of RNA which is then used to make proteins. RNA polymerase binds to a region just before the gene, called the promoter, before moving down the DNA to the gene.