Protein-Protein Interactions in the Cyanobacterial Circadian Clock: Structure of KaiA Dimer in Complex with C-Terminal KaiC Peptides at 2.8 Å Resolution
| Autor: | Rekha Pattanayek, Martin Egli |
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| Rok vydání: | 2015 |
| Předmět: |
Models
Molecular Synechococcus Circadian Rhythm Signaling Peptides and Proteins Protein subunit Circadian clock Mutant Biology Random hexamer Crystallography X-Ray Biochemistry Protein Structure Secondary Protein–protein interaction Bacterial Proteins KaiC Mutation Biophysics KaiA Phosphorylation Protein Multimerization Peptides Protein Structure Quaternary |
| Zdroj: | Biochemistry. 54(30) |
| ISSN: | 1520-4995 |
| Popis: | In the cyanobacterial circadian clock, the KaiA, -B, and -C proteins with ATP constitute a post-translational oscillator. KaiA stimulates the KaiC autokinase, and KaiB antagonizes KaiA action. KaiA contacts the intrinsically disordered C-terminal regions of KaiC hexamer to promote phosphorylation across subunit interfaces. The crystal structure of KaiA dimer from Synechococcus elongatus with two KaiC C-terminal 20mer peptides bound reveals that the latter adopt an α-helical conformation and contact KaiA α-helical bundles via mostly hydrophobic interactions. This complex and the crystal structure of KaiC hexamer with truncated C-terminal tails can be fit into the electron microscopy (EM) density of the KaiA:KaiC complex. The hybrid model helps rationalize clock phenotypes of KaiA and KaiC mutants. |
| Databáze: | OpenAIRE |
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