Anti-TFIID subunit 1/TAF1/CCG1/KAT4 antibody. TAFIID subunit1 (1,872 aa, 213 kDa) is the largest component and core scaffold of the TFIID basal transcription factor complex. It contains a novel N- and C-terminal Ser/Thr kinase domain which can autophosphorylate or transphosphorylate other transcription factors.