| Structural highlights
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.[1] [2]
Publication Abstract from PubMed
Cyanobacteria have a robust circadian oscillator, known as the Kai system. Reconstituted from the purified protein components KaiC, KaiB, and KaiA, it can tick autonomously in the presence of adenosine 5'-triphosphate (ATP). The KaiC hexamers enter a natural 24-hour reaction cycle of autophosphorylation and assembly with KaiB and KaiA in numerous diverse forms. We describe the preparation of stoichiometrically well-defined assemblies of KaiCB and KaiCBA, as monitored by native mass spectrometry, allowing for a structural characterization by single-particle cryo-electron microscopy and mass spectrometry. Our data reveal details of the interactions between the Kai proteins and provide a structural basis to understand periodic assembly of the protein oscillator.
Structures of the cyanobacterial circadian oscillator frozen in a fully assembled state.,Snijder J, Schuller JM, Wiegard A, Lossl P, Schmelling N, Axmann IM, Plitzko JM, Forster F, Heck AJ Science. 2017 Mar 17;355(6330):1181-1184. doi: 10.1126/science.aag3218. Epub 2017, Mar 16. PMID:28302852[3]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Ishiura M, Kutsuna S, Aoki S, Iwasaki H, Andersson CR, Tanabe A, Golden SS, Johnson CH, Kondo T. Expression of a gene cluster kaiABC as a circadian feedback process in cyanobacteria. Science. 1998 Sep 4;281(5382):1519-23. PMID:9727980
- ↑ Nakahira Y, Katayama M, Miyashita H, Kutsuna S, Iwasaki H, Oyama T, Kondo T. Global gene repression by KaiC as a master process of prokaryotic circadian system. Proc Natl Acad Sci U S A. 2004 Jan 20;101(3):881-5. Epub 2004 Jan 6. PMID:14709675 doi:10.1073/pnas.0307411100
- ↑ Snijder J, Schuller JM, Wiegard A, Lossl P, Schmelling N, Axmann IM, Plitzko JM, Forster F, Heck AJ. Structures of the cyanobacterial circadian oscillator frozen in a fully assembled state. Science. 2017 Mar 17;355(6330):1181-1184. doi: 10.1126/science.aag3218. Epub 2017, Mar 16. PMID:28302852 doi:http://dx.doi.org/10.1126/science.aag3218
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