Project description:Transcription preinitiation complex assembly on the promoters of protein encoding genes is nucleated in vivo by TFIID composed of the TATA-box Binding Protein (TBP) and 13 TBP-associate factors (Tafs) providing regulatory and chromatin binding functions. We used CXMS to study the organization and structure of the purified TFIID complex from Komagataella phaffii. Together with Cryo-EM, We confirm the unique subunit stoichiometry prevailing in TFIID and uncover a hexameric arrangement of Tafs containing a HF domain. Interaction with promoter DNA highlights two non-selective binding sites consistent with a DNA scanning mode.
