4F3L:
reference: Crystal structure of the heterodimeric CLOCK:BMAL1 transcriptional activator complex., Huang N, Chelliah Y, Shan Y, Taylor CA, Yoo SH, Partch C, Green CB, Zhang H, Takahashi JS, Science. 2012 Jul 13;337(6091):189-94. Epub 2012 May 31. PMID: 22653727

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