7S67

Extended conformation of daytime state KaiC

7S67 の概要

• エントリーDOI: 10.2210/pdb7s67/pdb
• EMDBエントリー: 24850 24851 24852
• 分子名称: Circadian clock protein kinase KaiC, ADENOSINE-5'-TRIPHOSPHATE, MAGNESIUM ION, ... (4 entities in total)
• 機能のキーワード: aaa atpase, circadian oscillator, kinase, phosphatase, circadian clock protein
• 由来する生物種: Synechococcus elongatus
• タンパク質・核酸の鎖数: 6
• 化学式量合計: 354406.64

構造登録者

Sandate, C.R.,Swan, J.A.,Partch, C.L.,Lander, G.C. (登録日: 2021-09-13, 公開日: 2021-09-22, 最終更新日: 2024-06-05)

主引用文献

Swan, J.A.,Sandate, C.R.,Chavan, A.G.,Freeberg, A.M.,Etwaru, D.,Ernst, D.C.,Palacios, J.G.,Golden, S.S.,LiWang, A.,Lander, G.C.,Partch, C.L.
Coupling of distant ATPase domains in the circadian clock protein KaiC.
Nat.Struct.Mol.Biol., 29:759-766, 2022

PubMed Abstract: The AAA family member KaiC is the central pacemaker for circadian rhythms in the cyanobacterium Synechococcus elongatus. Composed of two hexameric rings of adenosine triphosphatase (ATPase) domains with tightly coupled activities, KaiC undergoes a cycle of autophosphorylation and autodephosphorylation on its C-terminal (CII) domain that restricts binding of clock proteins on its N-terminal (CI) domain to the evening. Here, we use cryogenic-electron microscopy to investigate how daytime and nighttime states of CII regulate KaiB binding on CI. We find that the CII hexamer is destabilized during the day but takes on a rigidified C-symmetric state at night, concomitant with ring-ring compression. Residues at the CI-CII interface are required for phospho-dependent KaiB association, coupling ATPase activity on CI to cooperative KaiB recruitment. Together, these studies clarify a key step in the regulation of cyanobacterial circadian rhythms by KaiC phosphorylation.

PubMed: 35864165
DOI: 10.1038/s41594-022-00803-w

実験手法

ELECTRON MICROSCOPY (3.8 Å)