The parasite Toxoplasma gondii infects approximately 60 million Americans with an incurable chronic infection that presents a serious risk to pregnant women, their unborn babies, and immunocompromised people. We have identified a parasite factor called a bromodomain, that is critical for parasite survival during infection but its essential function is unknown. The goal of this proposal is to understand the function of this factor in the parasite, to support the development of effective new treatments for vulnerable people suffering from toxoplasmosis.