The cyclin-dependent kinase 8 module sterically blocks Mediator interactions with RNA polymerase II.
CDK8 (cyclin-dependent kinase 8), along with CycC, Med12, and Med13, form a repressive module (the Cdk8 module) that prevents RNA polymerase II (pol II) interactions with Mediator. Here, we report that the ability of the Cdk8 module to prevent pol II interactions is independent of the Cdk8-dependent kinase activity. We use electron microscopy and single-particle reconstruction to demonstrate that the Cdk8 module forms a distinct structural entity that binds to the head and middle region of Mediator, thereby sterically blocking interactions with pol II.
Elmlund
Hans
H
Department of Biosciences and Nutrition, Karolinska Institutet and School of Technology and Health, Royal Institute of Technology, Novum, SE-141 87 Huddinge, Sweden.
Baraznenok
Vera
V
Lindahl
Martin
M
Samuelsen
Camilla O
CO
Koeck
Philip J B
PJ
Holmberg
Steen
S
Hebert
Hans
H
Gustafsson
Claes M
CM
D056850:Cyclin-Dependent Kinase 8; D018844:Cyclin-Dependent Kinases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D020035:Holoenzymes / Q000737:chemistry / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure; D008854:Microscopy, Electron; D008958:Models, Molecular; D011485:Protein Binding; D020836:Protein Structure, Quaternary; D017434:Protein Structure, Tertiary; D012319:RNA Polymerase II / Q000737:chemistry / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D012568:Schizosaccharomyces / Q000737:chemistry / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure; D029702:Schizosaccharomyces pombe Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure
D020035:Holoenzymes; D029702:Schizosaccharomyces pombe Proteins; D056850:Cyclin-Dependent Kinase 8; D018844:Cyclin-Dependent Kinases; C112462:srb10 protein, S pombe; D012319:RNA Polymerase II