5efq | pdb_00005efq
Crystal structure of human Cdk13/Cyclin K in complex with ADP-aluminum fluoride
Structural highlights
Function[CDK13_HUMAN] Cyclin-dependent kinase which displays CTD kinase activity and is required for RNA splicing. Has CTD kinase activity by hyperphosphorylating the C-terminal heptapeptide repeat domain (CTD) of the largest RNA polymerase II subunit RPB1, thereby acting as a key regulator of transcription elongation. Required for RNA splicing, probably by phosphorylating SRSF1/SF2. Required during hematopoiesis. In case of infection by HIV-1 virus, interacts with HIV-1 Tat protein acetylated at 'Lys-50' and 'Lys-51', thereby increasing HIV-1 mRNA splicing and promoting the production of the doubly spliced HIV-1 protein Nef.[1] [2] [3] [4] [CCNK_HUMAN] May play a role in transcriptional regulation. In vitro, is associated with a kinase activity toward both RNA polymerase II C-terminal domain and CDK2 (CAK).[5] Publication Abstract from PubMedCyclin-dependent kinases regulate the cell cycle and transcription in higher eukaryotes. We have determined the crystal structure of the transcription kinase Cdk13 and its Cyclin K subunit at 2.0 A resolution. Cdk13 contains a C-terminal extension helix composed of a polybasic cluster and a DCHEL motif that interacts with the bound ATP. Cdk13/CycK phosphorylates both Ser5 and Ser2 of the RNA polymerase II C-terminal domain (CTD) with a preference for Ser7 pre-phosphorylations at a C-terminal position. The peptidyl-prolyl isomerase Pin1 does not change the phosphorylation specificities of Cdk9, Cdk12, and Cdk13 but interacts with the phosphorylated CTD through its WW domain. Using recombinant proteins, we find that flavopiridol inhibits Cdk7 more potently than it does Cdk13. Gene expression changes after knockdown of Cdk13 or Cdk12 are markedly different, with enrichment of growth signaling pathways for Cdk13-dependent genes. Together, our results provide insights into the structure, function, and activity of human Cdk13/CycK. Structural and Functional Analysis of the Cdk13/Cyclin K Complex.,Greifenberg AK, Honig D, Pilarova K, Duster R, Bartholomeeusen K, Bosken CA, Anand K, Blazek D, Geyer M Cell Rep. 2016 Jan 12;14(2):320-31. doi: 10.1016/j.celrep.2015.12.025. Epub 2015 , Dec 31. PMID:26748711[6] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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