4nst
From Proteopedia
Crystal structure of human Cdk12/Cyclin K in complex with ADP-aluminum fluoride
Structural highlights
DiseaseCDK12_HUMAN Chromosomal aberrations involving CDK12 may be a cause gastric cancer. Deletions within 17q12 region producing fusion transcripts with ERBB2, leading to CDK12-ERBB2 fusion leading to trunctated CDK12 protein not in-frame with ERBB2. FunctionCDK12_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, possibly by phosphorylating SRSF1/SF2. Involved in regulation of MAP kinase activity, possibly leading to affect the response to estrogn inhibitors.[1] [2] [3] Publication Abstract from PubMedPhosphorylation of the RNA polymerase II C-terminal domain (CTD) by cyclin-dependent kinases is important for productive transcription. Here we determine the crystal structure of Cdk12/CycK and analyse its requirements for substrate recognition. Active Cdk12/CycK is arranged in an open conformation similar to that of Cdk9/CycT but different from those of cell cycle kinases. Cdk12 contains a C-terminal extension that folds onto the N- and C-terminal lobes thereby contacting the ATP ribose. The interaction is mediated by an HE motif followed by a polybasic cluster that is conserved in transcriptional CDKs. Cdk12/CycK showed the highest activity on a CTD substrate prephosphorylated at position Ser7, whereas the common Lys7 substitution was not recognized. Flavopiridol is most potent towards Cdk12 but was still 10-fold more potent towards Cdk9. T-loop phosphorylation of Cdk12 required coexpression with a Cdk-activating kinase. These results suggest the regulation of Pol II elongation by a relay of transcriptionally active CTD kinases. The structure and substrate specificity of human Cdk12/Cyclin K.,Bosken CA, Farnung L, Hintermair C, Merzel Schachter M, Vogel-Bachmayr K, Blazek D, Anand K, Fisher RP, Eick D, Geyer M Nat Commun. 2014 Mar 24;5:3505. doi: 10.1038/ncomms4505. PMID:24662513[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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