Description_x000D_ Biochem/physiol Actions_x000D_ The transcription factor IIA (TFIIA) has been shown to bind to the TBP-DNA complex and to increase the affinity of TBP for the TATA element. Human TFIIA consists of three subunits of 35 kDa ( α subunit), 19 kDa ( β subunit) and 12 kDa ( γ subunit). The α and β subunits are derived from the product, p55, of a single gene by an unknown mechanism. However, recombinant p55, in combination with a 12 kDa subunit ( γ subunit), retains native TFIIA activity._x000D_ Physical form_x000D_ Clear and colorless frozen liquid solution_x000D_ Preparation Note_x000D_ Use a manual defrost freezer and avoid repeated freeze-thaw cycles. While working, please keep sample on ice.