Functions as a component of the DNA-binding general transcription factor complex TFIID, and the RNA polymerase II associated general transcription factor complex TFIIF. Binding of TFIID to a promoter (with or without TATA element) is the initial step in preinitiation complex (PIC) formation. TFIID plays a key role in the regulation of gene expression by RNA polymerase II through different activities such as transcription activator interaction, core promoter recognition and selectivity, TFIIA and TFIIB interaction, facilitation of DNA opening and initiation of transcription. TFIIF is essential for the initiation of transcription by RNA polymerase II. TFIIF functions include the recruitment of RNA polymerase II to the promoter bound DNA-TBP-TFIIB complex, decreasing the affinity of RNA polymerase II for non-specific DNA, allowing for the subsequent recruitment of TFIIE and TFIIH, and facilitating RNA polymerase II elongation. The TAF14 subunit has stimulatory activity. Component of the SWI/SNF complex, an ATP-dependent chromatin remodeling complex, required for the positive and negative regulation of gene expression of a large number of genes. It changes chromatin structure by altering DNA-histone contacts within a nucleosome, leading eventually to a change in nucleosome position, thus facilitating or repressing binding of gene-specific transcription factors. Component of the mst2 complex which is a highly specific H3 lysine 14 (H3K14) acetyltransferase that functions together with gcn5 to regulate global levels of H3K14 acetylation (H3K14ac), critical for DNA damage checkpoint activation. Component of the fcp1/TFIIF/polII complex via interaction of tfg3 with both tfg1/TFIIF-alpha and tfg2/TFIIF-beta subunits. Component of the SWI/SNF global transcription activator complex composed of at least arp9, arp42, snf5, snf22, snf30, sbf59, sol1, ssr1, ssr2, ssr3, ssr4 and tfg3. Interacts also with the TATA-binding protein (TBP). Component of the mst2 complex composed of at least eaf6, mst2, nto1, pdp3, ptf1, ptf2 and tfg3. Belongs to the TAF14 family.