The assembly and stability of the RNA polymerase II transcription pre-initiation complex on a eukaryotic core promoter involve the effects of TFIIA on the interaction between TATA-binding protein (TBP) and DNA. This gene encodes a germ cell-specific counterpart of the large (alpha/beta) subunit of general transcription factor TFIIA that is able to stabilize the binding of TBP to DNA and may be uniquely important to testis biology.