2gbl

Crystal Structure of Full Length Circadian Clock Protein KaiC with Phosphorylation Sites

spinqualitylabelsall models 2gbl, resolution 2.80Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2gbl is a 6 chain structure with sequence from Synechococcus elongatus PCC 7942 = FACHB-805. The January 2008 RCSB PDB Molecule of the Month feature on Circadian Clock Proteins by David S. Goodsell is 10.2210/rcsb_pdb/mom_2008_1. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.8Å Ligands: ATP, MG, SEP, TPO Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function KAIC_SYNE7 Core component of the KaiABC clock protein complex, which constitutes the main circadian regulator in cyanobacteria. Binds to DNA. The KaiABC complex may act as a promoter-nonspecific transcription regulator that represses transcription, possibly by acting on the state of chromosome compaction. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed The cyanobacterial circadian clock can be reconstituted in vitro by mixing recombinant KaiA, KaiB and KaiC proteins with ATP, producing KaiC phosphorylation and dephosphorylation cycles that have a regular rhythm with a ca. 24-h period and are temperature-compensated. KaiA and KaiB are modulators of KaiC phosphorylation, whereby KaiB antagonizes KaiA's action. Here, we present a complete crystallographic model of the Synechococcus elongatus KaiC hexamer that includes previously unresolved portions of the C-terminal regions, and a negative-stain electron microscopy study of S. elongatus and Thermosynechococcus elongatus BP-1 KaiA-KaiC complexes. Site-directed mutagenesis in combination with EM reveals that KaiA binds exclusively to the CII half of the KaiC hexamer. The EM-based model of the KaiA-KaiC complex reveals protein-protein interactions at two sites: the known interaction of the flexible C-terminal KaiC peptide with KaiA, and a second postulated interaction between the apical region of KaiA and the ATP binding cleft on KaiC. This model brings KaiA mutation sites that alter clock period or abolish rhythmicity into contact with KaiC and suggests how KaiA might regulate KaiC phosphorylation. Analysis of KaiA-KaiC protein interactions in the cyano-bacterial circadian clock using hybrid structural methods.,Pattanayek R, Williams DR, Pattanayek S, Xu Y, Mori T, Johnson CH, Stewart PL, Egli M EMBO J. 2006 May 3;25(9):2017-28. Epub 2006 Apr 20. PMID:16628225 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Circadian clock protein 3D structures

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