This gene encodes one of the three subunits of the RNA polymerase III transcription factor complex. This complex plays a central role in transcription initiation by RNA polymerase III on genes encoding tRNA, 5S rRNA, and other small structural RNAs. The gene product belongs to the TF2B family. Two alternatively spliced variants encoding different isoforms, that function at different promoters transcribed by RNA polymerase III, have been identified. Other transcript variants are possible, but their full-length natures have not been completely characterized. [provided by RefSeq].