Transcription of GAL10 and GAL1 is controlled by the (UASG), which is kept constitutively open (DNase sensitive - free of nucleosome), by the SWI/SNF remodeling complex.

In the absence of galactose, Gal80 proteins are bound to UASG via Gal4 proteins so that the latter's activation domains (dark patches) are covered.

Galactose acts as an inducer by binding to the complex and exposing the activation domains, enhancing transcription.