Abstract
DNA is crucial to life. This molecule rests at the heart of a cell nucleus, stands in between most important metabolic pathways, and provides the basis for genetic information flow. However does it really just rest? Is that big and early invention of evolution limited to the inert function of information storage? To address this we tackle several aspects of DNA structure. Each of them may become crucial when the molecule changes its role — when it serves as a blueprint for copying, a site for precise binding of proteins, or is involved in complex and dynamic interactions with them. We focus on promoters which initiate the process of transcription, i.e. the “rewriting” of DNA into RNA. Our setting is the tiny genome of bacteriophage T7 and its petite, very similar yet very distinct promoters.