Part of the general transcription factor complex TFIID (By similarity). Plays a role in recruiting taf-4 to the nucleus and thereby activating transcription initiation by RNA polymerase II, as part of the TFIID complex (PubMed:18854162). Interacts (via histone-fold domain) with taf-4 (via the histone-fold domain) (PubMed:18854162). Interaction may facilitate the nuclear localization of taf-4 (PubMed:18854162). Localized to nucleus throughout early embryogenesis. The histone-fold domain mediates hetero-dimer protein-protein interactions. RNAi-mediated knockdown reduces nuclear localization of taf-4. Belongs to the TAF12 family.