TFIIA is a component of the transcription machinery of RNA polymerase II and plays an important role in transcriptional activation (PubMed:7958898). TFIIA in a complex with TBP mediates transcriptional activity (PubMed:7958898). Part of a rhi-dependent transcription machinery that enables the generation of piRNA precursors from heterochromatin while maintaining the suppression of transposon-encoded promoters and enhancers (PubMed:28847004). Forms a complex with Moonshiner/CG12721 and Trf2 which recruit transcriptional machinery to heterochromatin to initiate the bidirectional transcription of piRNA clusters, by interacting with the RDC (rhi, del and cuff) complex that binds to repressive H3K9me3 marks in the chromatin (PubMed:28847004). This mechanism allows transcription to occur in piRNA clusters despite the lack of proper promoter elements and in the presence of the repressive H3K9me3 mark (PubMed:28847004). TFIIA is a heterodimer of the large unprocessed subunit 1 and a small subunit gamma (PubMed:7958898). It was originally believed to be a heterotrimer of an alpha (p30), a beta (p20) and a gamma (p14) subunit (PubMed:7958898). Forms a complex with Moonshiner/CG12721 and Trf2 (PubMed:28847004). Ubiquitous. Females are sterile. Belongs to the TFIIA subunit 2 family.