Molecular architecture of the yeast Mediator complex

The 21-subunit Mediator complex transduces regulatory information from enhancers to promoters, and performs an essential role in the initiation of transcription in all eukaryotes. This repository contains files used in the 3-D modeling of the entire Mediator complex, using an integrative modeling approach that combines information from chemical cross-linking and mass spectrometry; X-ray crystallography; homology modeling; and cryo-electron microscopy. The approach is validated by the use of X-ray crystal structures as internal controls and by consistency with previous results from electron microscopy and yeast two-hybrid screens. The model shows the locations and orientations of all Mediator subunits, as well as subunit interfaces and some secondary structural elements. Segments of 20–40 amino acid residues are placed with an average precision of 20 Å. The model reveals roles of individual subunits in the organization of the complex.