The basal RNA polymerase II transcription factor, TFIID, is composed of the TATA binding protein (TBP) and 8-13 TBP-associated factors (TAFs) ranging from 250 to 17 kDa. The structure of the human gene encoding the 30-kDa subunit of TFIID, TAF2H, has been determined. The gene consists of five exons (ranging from 66 to 248 bp) and four introns (ranging from 83 to 211 bp). The transcription start site of the mRNA was mapped, and it shares a weak homology to the consensus of known initiator elements. Using in situ hybridization on human metaphase chromosomes, the TAF2H gene has been localized in the 11p15.2-p15.5 region of the human genome.