Researchers from the University of California, Berkeley, and the Howard Hughes Medical Institute (HHMI) have been working on this project for more than 20 years. Their findings, published in the journal Nature, provide important new insights into how genes are regulated.

The protein, called the activator-binding domain (ABD) of the yeast Gal4 transcription factor, is a key part of the molecular switch that turns genes "on."

The ABD binds to DNA and recruits other proteins that are needed to initiate transcription, the process of copying DNA into RNA. When the ABD is bound to DNA, the switch is in the "on" position; when the ABD is not bound to DNA, the switch is in the "off" position.

The researchers used X-ray crystallography to determine the structure of the ABD in atomic detail.

This structure reveals how the ABD binds to DNA and how it interacts with other proteins. The structure also provides clues about how the ABD is regulated.

The findings provide new insights into how genes are regulated.

The structure of the ABD could help researchers to design new drugs that target the ABD and control gene expression. This could lead to new treatments for a variety of diseases, including cancer and diabetes.