TAF1 is the largest component of transcription factor TFIID that is composed of TBP and a variety of TBP-associated factors. TAF1, when part of the TFIID complex, interacts with C-terminus of TP53. Component of some MLL1/MLL complex, at least composed of the core components MLL, ASH2L, HCFC1/HCF1, WDR5 and RBBP5, as well as the facultative components C17orf49, CHD8, E2F6, HSP70, INO80C, KANSL1, LAS1L, MAX, MCRS1, MGA, KAT8/MOF, PELP1, PHF20, PRP31, RING2, RUVB1/TIP49A, RUVB2/TIP49B, SENP3, TAF1, TAF4, TAF6, TAF7, TAF9 and TEX10. RB1 interacts with the N-terminal domain of TAF1. Interacts with ASF1A and ASF1B. Interacts with SV40 Large T antigen.