This family consists of several eukaryotic proteins which are homologues of the yeast MED7 protein. Activation of gene transcription in metazoans is a multi-step process that is triggered by factors that recognise transcriptional enhancer sites in DNA. These factors work with co-activators such as MED7 to direct transcriptional initiation by the RNA polymerase II apparatus [1].

1: The transcriptional cofactor complex CRSP is required for activity of the enhancer-binding protein Sp1. Ryu S, Zhou S, Ladurner AG, Tjian R; Nature 1999;397:446-450. PMID:9989412