Fig. 1: Structure of the doubly phosphorylated Cdk7/Cyclin H/Mat1 complex.
From: Structural basis of Cdk7 activation by dual T-loop phosphorylation
a SDS-PAGE analysis and immunoblotting of Cdk7/Cyclin H/Mat1 complexes. Protein (3 µg) was resolved in a 15% SDS-polyacrylamide gel and stained with Coomassie blue. Note the difference in migration behavior of Cdk7 depending on the phosphorylation status; doubly phosphorylated Cdk7 and Cyclin H migrate at the same size. For immunoblot analysis of the Cdk7 T-loop phosphorylation status, 1 µL protein at 2.6 µM was resolved by SDS-PAGE, transferred to nitrocellulose and probed with phospho-specific antibodies recognizing Cdk7 pT170 or Cdk7 pS164. b Alignment of transcriptional CDK T loops. c, Radiometric kinase assay probing the preparations for activity towards RNAPII CTD. Each Cdk7 complex (0.1 µM) was incubated with 10 µM GST-CTD[52] in the presence of 1 mM ATP containing 0.35 µCi [32P]-γ-ATP for 15 min at 30 °C. Bars represent mean of duplicate measurement. d, Crystal structure of the doubly T-loop phosphorylated Cdk7/Cyclin H/Mat1/VHHRD7-04 complex at 2.15 Å resolution. Source data are provided as a Source Data file.
