TATA Box Binding Protein Associated Factor 1 Like Protein (TAF1L)

TAF1L spans 6.5 kb on chromosome 9, and encodes an 1,826-residue protein with 95% amino acid identity to TAFII250. TAF1L lacks introns and evidently arose by retroposition of a processed TAFII250 mRNA during primate evolution. TFIID is a DNA-binding protein complex required for RNA polymerase II-mediated transcription of many, if not all, protein-encoding genes in eukaryotic cells .

Like TAFII250, the human TAF1L protein can bind directly to TATA-binding protein, an essential component of TFIID. Transfection with human TAF1L rescued the temperature-sensitive lethality of a hamster cell line mutant in TAFII250. The authors hypothesized that during male meiosis, transcription of protein-encoding genes may rely upon TAF1L as a functional substitute for TAFII250.