5CE7

Structure of a non-canonical CID of Ctk3

Summary for 5CE7

• Entry DOI: 10.2210/pdb5ce7/pdb
• Descriptor: CTD kinase subunit gamma, 4-(2-HYDROXYETHYL)-1-PIPERAZINE ETHANESULFONIC ACID (3 entities in total)
• Functional Keywords: lsg1, ctd kinase subunit gamma, right-handed superhelix, transcription
• Biological source: Schizosaccharomyces pombe (Fission yeast)
• Cellular location: Cytoplasm : Q9USJ8
• Total number of polymer chains: 1
• Total formula weight: 16461.96

Authors

Muehlbacher, W.,Mayer, A.,Sun, M.,Remmert, M.,Cheung, A.C.,Niesser, J.,Soeding, J.,Cramer, P. (deposition date: 2015-07-06, release date: 2015-08-05, Last modification date: 2015-09-16)

Primary citation

Muhlbacher, W.,Mayer, A.,Sun, M.,Remmert, M.,Cheung, A.C.,Niesser, J.,Soeding, J.,Cramer, P.
Structure of Ctk3, a subunit of the RNA polymerase II CTD kinase complex, reveals a noncanonical CTD-interacting domain fold.
Proteins, 83:1849-1858, 2015

PubMed Abstract: CTDK-I is a yeast kinase complex that phosphorylates the C-terminal repeat domain (CTD) of RNA polymerase II (Pol II) to promote transcription elongation. CTDK-I contains the cyclin-dependent kinase Ctk1 (homologous to human CDK9/CDK12), the cyclin Ctk2 (human cyclin K), and the yeast-specific subunit Ctk3, which is required for CTDK-I stability and activity. Here we predict that Ctk3 consists of a N-terminal CTD-interacting domain (CID) and a C-terminal three-helix bundle domain. We determine the X-ray crystal structure of the N-terminal domain of the Ctk3 homologue Lsg1 from the fission yeast Schizosaccharomyces pombe at 2.0 Å resolution. The structure reveals eight helices arranged into a right-handed superhelical fold that resembles the CID domain present in transcription termination factors Pcf11, Nrd1, and Rtt103. Ctk3 however shows different surface properties and no binding to CTD peptides. Together with the known structure of Ctk1 and Ctk2 homologues, our results lead to a molecular framework for analyzing the structure and function of the CTDK-I complex.

PubMed: 26219431
DOI: 10.1002/prot.24869

Experimental method

X-RAY DIFFRACTION (2 Å)