The TFIID basal transcription factor complex plays a major role in the initiation of RNA polymerase II (Pol II)-dependent transcription (By similarity). TFIID recognizes and binds promoters with or without a TATA box via its subunit TBP, a TATA-box-binding protein, and promotes assembly of the pre-initiation complex (PIC) (By similarity). The TFIID complex consists of TBP and TBP-associated factors (TAFs), including TAF1, TAF2, TAF3, TAF4, TAF5, TAF6, TAF7, TAF8, TAF9, TAF10, TAF11, TAF12 and TAF13 (By similarity). The TFIID complex structure can be divided into 3 modules TFIID-A, TFIID-B, and TFIID-C (By similarity). TAF3 forms the TFIID-A module together with TAF5 and TBP (By similarity). Required in complex with TBPL2 for the differentiation of myoblasts into myocytes (PubMed:17704303). The TAF3-TBPL2 complex replaces TFIID at specific promoters at an early stage in the differentiation process (PubMed:17704303). Component of the TFIID basal transcription factor complex, composed of TATA-box-binding protein TBP, and a number of TBP-associated factors (TAFs), including TAF1, TAF2, TAF3, TAF4, TAF5, TAF6, TAF7, TAF8, TAF9, TAF10, TAF11, TAF12 and TAF13 (By similarity). Interacts with TAF10 via histone fold (PubMed:11438666). Interacts with TAF13, TBP, SAP130 and GCN5L2 (By similarity). Interacts with TBPL2 (PubMed:17704303). The PHD-type zinc finger mediates binding to histone H3 methyllysine at position 4 (H3K4me3). Belongs to the TAF3 family.