Mediator is a protein complex which performs a very important role both for the transcription at the basal level which does not rely on transcription control factor and the transcription activating reaction that relies on the transcription control factor. It has the characteristic of binding to the 7 amino acid repeated structure (CTD) that exists in the C terminal of the biggest subunit of RNA polymerase II. 30 kinds of subunits have already being identified as its composing substance, but it is said that multiple kinds of complex with varied subunit compositions exist in the cells. Gal11p is one of the mediator subunit and is composed of 1081 amino acid residues (aa). A^