In some cases, nucleosomes are precisely positioned, in part because the DNA sequence favors certain locations and in part as a result of specific regulatory events. Reduce positive charge of histones, giving weaker DNA binding b. Destabilize interactions between nucleosomes 3. It is important to understand these methods, and to be aware of the capabilities and limitations of each method. Here are some general principles, for your own information. I won't ask specifically about these on the exam.
Positive regulation is thought to overcome rate-limiting steps.
Many regulated promoters contain binding sites for constitutively expressed factors. There are multigene families of closely related DNA binding proteins with similar or identical sequence specificity. Different proteins can bind to the same or closely related sequence. Maybe other factors help confer specificity. All rights reserved.