TFB2 is a transient component of the catalytic site of the human mitochondrial RNA polymerase.
Sologub M, Litonin D, Anikin M, Mustaev A, Temiakov D. TFB2 is a transient component of the catalytic site of the human mitochondrial RNA polymerase. Cell. 2009 Nov 25; 139(5):934-44.