This superfamily includes mediator, a multiprotein complex that regulates transcription by interacting with RNA polymerase II and transcription activators and repressors. The entry represents Med31 subunit (known as Soh1 in Saccharomyces cerevisiae) and its homologues.

The middle module of the mediator core contains a submodule of unique structure and function that comprises the N-terminal part of subunit Med7 (Med7N) and the highly conserved subunit Med31, organised as a four helix bundle. In vivo, Med7N/31 has a predominantly positive function on the expression of a specific subset of genes, including genes involved in methionine metabolism and iron transport PMID:19057509.

Soh1 is responsible for the repression of temperature sensitive growth of the Hpr1 mutant PMID:7982575 and has been found to be a component of the RNA polymerase II transcription complex. Soh1 not only interacts with factors involved in DNA repair, but transcription as well. Thus, the Soh1 protein may serve to couple these two processes PMID:8849885.

PFAM:PF05669,INTERPRO:IPR008831,DOI:10.1038/emboj.2008.254