Identification, structure, and functional requirement of the Mediator submodule Med7N/31.
Mediator is a modular multiprotein complex required for regulated transcription by RNA polymerase (Pol) II. Here, we show that 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 (Soh1). The Med7N/31 submodule shows a conserved novel fold, with two proline-rich stretches in Med7N wrapping around the right-handed four-helix bundle of Med31. In vitro, Med7N/31 is required for activated transcription and can act in trans when added exogenously. 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. Comparative phenotyping and transcriptome profiling identify specific and overlapping functions of different Mediator submodules.
Koschubs
Tobias
T
Gene Center and Center for Integrated Protein Science Munich (CIPSM), Department of Chemistry and Biochemistry, Ludwig-Maximilians-Universität (LMU) München, Munich, Germany.
Seizl
Martin
M
Larivière
Laurent
L
Kurth
Fabian
F
Baumli
Sonja
S
Martin
Dietmar E
DE
Cramer
Patrick
P
D000595:Amino Acid Sequence; D018360:Crystallography, X-Ray; D029721:Drosophila Proteins / Q000737:chemistry* / Q000378:metabolism*; D005816:Genetic Complementation Test; D056892:Mediator Complex; D008958:Models, Molecular; D008969:Molecular Sequence Data; D020836:Protein Structure, Quaternary; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000254:growth & development; D016415:Sequence Alignment; D015534:Trans-Activators / Q000737:chemistry* / Q000378:metabolism*; D014157:Transcription Factors / Q000737:chemistry* / Q000378:metabolism*; D014158:Transcription, Genetic
D029721:Drosophila Proteins; C526783:Med31 protein, Drosophila; D056892:Mediator Complex; D015534:Trans-Activators; D014157:Transcription Factors