Mapping the D.melanogaster En1A Enhancer Modules Responsible for Transcription Activation and Long-Distance Enhancer-Promoter Interactions

The structure of the new enhancer En1A of the 1A region of the X chromosome of D. melanogasterwas investigated. Two distinct regulatory elements were found. The first element is responsible for transcrip-tion activation, and the second element provides specific interaction with the promoter of the yellow gene. The findings support the hypothesis of a modular structure for enhancers, including certain sequences that bind transcription activators and special communication elements providing long-distance enhancer-promoter in-teraction.