Model of the Mediator middle module based on protein cross-linking.
The essential core of the transcription coactivator Mediator consists of two conserved multiprotein modules, the head and middle modules. Whereas the structure of the head module is known, the structure of the middle module is lacking. Here we report a 3D model of a 6-subunit Mediator middle module. The model was obtained by arranging crystal structures and homology models of parts of the module based on lysine-lysine cross-links obtained by mass spectrometric analysis. The model contains a central tetramer formed by the heterodimers Med4/Med9 and Med7/Med21. The Med7/Med21 heterodimer is flanked by subunits Med10 and Med31. The model is highly extended, suggests that the middle module is flexible and contributes to a molecular basis for detailed structure-function studies of RNA polymerase II regulation.
Gene Center Munich and Department of Biochemistry, Center for Integrated Protein Science Munich (CIPSM), Ludwig-Maximilians-Universität München, Feodor-Lynen-Str. 25, 81377 Munich, Germany and Department of Biochemistry and Microbiology, Genome British Columbia Protein Centre, University of Victoria, No. 3101-4464 Markham Street, Vancouver Island Technology Park, Victoria, BC V8Z7X8, Canada.
Laurent
L
Larivière
Clemens
C
Plaschka
Martin
M
Seizl
Evgeniy V
EV
Petrotchenko
Larissa
L
Wenzeck
Christoph H
CH
Borchers
Patrick
P
Cramer
D056892:Mediator Complex / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D008958:Models, Molecular; D021122:Protein Subunits / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000302:isolation & purification / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry
C082275:CSE2 protein, S cerevisiae; C110184:MED7 protein, S cerevisiae; D056892:Mediator Complex; C113770:NUT2 protein, S cerevisiae; D021122:Protein Subunits; D011994:Recombinant Proteins; C492627:SOH1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins