Download MendeleyCrystal Structure of the CLOCK Transactivation Domain Exon19 in Complex with a Repressor.
Hou, Z., Su, L., Pei, J., Grishin, N.V., Zhang, H.(2017) Structure 25: 1187-1194.e3
- PubMed: 28669630
- DOI: https://doi.org/10.1016/j.str.2017.05.023
- Primary Citation of Related Structures:
5VJI, 5VJX - PubMed Abstract:
In the canonical clock model, CLOCK:BMAL1-mediated transcriptional activation is feedback regulated by its repressors CRY and PER and, in association with other coregulators, ultimately generates oscillatory gene expression patterns. How CLOCK:BMAL1 interacts with coregulator(s) is not well understood. Here we report the crystal structures of the mouse CLOCK transactivating domain Exon19 in complex with CIPC, a potent circadian repressor that functions independently of CRY and PER. The Exon19:CIPC complex adopts a three-helical coiled-coil bundle conformation containing two Exon19 helices and one CIPC. Unique to Exon19:CIPC, three highly conserved polar residues, Asn341 of CIPC and Gln544 of the two Exon19 helices, are located at the mid-section of the coiled-coil bundle interior and form hydrogen bonds with each other. Combining results from protein database search, sequence analysis, and mutagenesis studies, we discovered for the first time that CLOCK Exon19:CIPC interaction is a conserved transcription regulatory mechanism among mammals, fish, flies, and other invertebrates.
Organizational Affiliation:
Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
