Publication Date:
2012-06-02
Description:
The circadian clock in mammals is driven by an autoregulatory transcriptional feedback mechanism that takes approximately 24 hours to complete. A key component of this mechanism is a heterodimeric transcriptional activator consisting of two basic helix-loop-helix PER-ARNT-SIM (bHLH-PAS) domain protein subunits, CLOCK and BMAL1. Here, we report the crystal structure of a complex containing the mouse CLOCK:BMAL1 bHLH-PAS domains at 2.3 A resolution. The structure reveals an unusual asymmetric heterodimer with the three domains in each of the two subunits--bHLH, PAS-A, and PAS-B--tightly intertwined and involved in dimerization interactions, resulting in three distinct protein interfaces. Mutations that perturb the observed heterodimer interfaces affect the stability and activity of the CLOCK:BMAL1 complex as well as the periodicity of the circadian oscillator. The structure of the CLOCK:BMAL1 complex is a starting point for understanding at an atomic level the mechanism driving the mammalian circadian clock.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3694778/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉 〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3694778/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Huang, Nian -- Chelliah, Yogarany -- Shan, Yongli -- Taylor, Clinton A -- Yoo, Seung-Hee -- Partch, Carrie -- Green, Carla B -- Zhang, Hong -- Takahashi, Joseph S -- R01 GM081875/GM/NIGMS NIH HHS/ -- R01 GM090247/GM/NIGMS NIH HHS/ -- Howard Hughes Medical Institute/ -- New York, N.Y. -- Science. 2012 Jul 13;337(6091):189-94. doi: 10.1126/science.1222804. Epub 2012 May 31.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/22653727" target="_blank"〉PubMed〈/a〉
Keywords:
ARNTL Transcription Factors/*chemistry/genetics/metabolism
;
Amino Acid Sequence
;
Animals
;
CLOCK Proteins/*chemistry/genetics/metabolism
;
Cells, Cultured
;
*Circadian Rhythm
;
Crystallography, X-Ray
;
DNA/metabolism
;
HEK293 Cells
;
Helix-Loop-Helix Motifs
;
Humans
;
Mice
;
Models, Molecular
;
Molecular Sequence Data
;
Mutant Proteins/chemistry/metabolism
;
Protein Binding
;
Protein Interaction Domains and Motifs
;
Protein Multimerization
;
Protein Structure, Quaternary
;
Protein Structure, Secondary
;
Protein Structure, Tertiary
;
Protein Subunits/chemistry/metabolism
;
Static Electricity
;
*Transcriptional Activation
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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