Structure of the human Mediator-bound transcription preinitiation complex

R Abdella; A Talyzina; S Chen; C J Inouye; R Tjian; Y He

doi:10.1126/science.abg3074

Structure of the human Mediator-bound transcription preinitiation complex

Science. 2021 Apr 2;372(6537):52-56. doi: 10.1126/science.abg3074. Epub 2021 Mar 11.

Authors

R Abdella^#^{1

2}, A Talyzina^#^{1

2}, S Chen^{1

2}, C J Inouye^{3

4

5

6}, R Tjian^{7

4

5

6}, Y He^{8

2

9

10}

Affiliations

¹ Department of Molecular Biosciences, Northwestern University, Evanston, IL, USA.
² Interdisciplinary Biological Sciences Program, Northwestern University, Evanston, IL, USA.
³ Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA.
⁴ Li Ka Shing Center for Biomedical and Health Sciences, University of California, Berkeley, Berkeley, CA, USA.
⁵ CIRM Center of Excellence, University of California, Berkeley, Berkeley, CA, USA.
⁶ Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA, USA.
⁷ Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA. yuanhe@northwestern.edu jmlim@berkeley.edu.
⁸ Department of Molecular Biosciences, Northwestern University, Evanston, IL, USA. yuanhe@northwestern.edu jmlim@berkeley.edu.
⁹ Chemistry of Life Processes Institute, Northwestern University, Evanston, IL, USA.
¹⁰ Robert H. Lurie Comprehensive Cancer Center of Northwestern University, Northwestern University, Chicago, IL, USA.

^# Contributed equally.

Abstract

Eukaryotic transcription requires the assembly of a multisubunit preinitiation complex (PIC) composed of RNA polymerase II (Pol II) and the general transcription factors. The coactivator Mediator is recruited by transcription factors, facilitates the assembly of the PIC, and stimulates phosphorylation of the Pol II C-terminal domain (CTD) by the TFIIH subunit CDK7. Here, we present the cryo-electron microscopy structure of the human Mediator-bound PIC at a resolution below 4 angstroms. Transcription factor binding sites within Mediator are primarily flexibly tethered to the tail module. CDK7 is stabilized by multiple contacts with Mediator. Two binding sites exist for the Pol II CTD, one between the head and middle modules of Mediator and the other in the active site of CDK7, providing structural evidence for Pol II CTD phosphorylation within the Mediator-bound PIC.

Publication types

Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't

MeSH terms

Binding Sites
Catalytic Domain
Cryoelectron Microscopy
Cyclin-Dependent Kinase-Activating Kinase
Cyclin-Dependent Kinases / chemistry
Cyclin-Dependent Kinases / metabolism
Humans
Mediator Complex / chemistry*
Mediator Complex / metabolism
Models, Molecular
Phosphorylation
Protein Binding
Protein Domains
Protein Subunits / chemistry
Protein Subunits / metabolism
RNA Polymerase II / chemistry*
Transcription Factor TFIIH / chemistry
Transcription Factor TFIIH / metabolism
Transcription Factors, General / chemistry*
Transcription Factors, General / metabolism
Transcription Initiation, Genetic*

Substances

Mediator Complex
Protein Subunits
Transcription Factors, General
Transcription Factor TFIIH
Cyclin-Dependent Kinases
RNA Polymerase II
Cyclin-Dependent Kinase-Activating Kinase
CDK7 protein, human

Abstract

Publication types

MeSH terms

Substances

Grants and funding