Two opposing teams battle it out to regulate gene expression on the DNA playing field. One, the activators, keeps DNA open to enzymes that transcribe DNA into RNA. Their repressor opponents antagonize that effort by twisting DNA into an inaccessible coil around histone proteins, an amalgam called chromatin, effectively blocking access to DNA by enzymes that elongate an RNA strand. Both teams maneuver by chemically modifying histones - the activators by decorating histones with acetyl groups - let's call them green flags - causing them to loosen their grip on DNA...
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