- A motif shared by TFIIF and TFIIB mediates their interaction with the RNA polymerase II carboxy-terminal domain phosphatase Fcp1p in Saccharomyces cerevisiae. Kobor, M.S., Simon, L.D., Omichinski, J., Zhong, G., Archambault, J., Greenblatt, J. Mol. Cell. Biol. (2000)