Zinc binding and disulfide bonds influence how key body clock proteins CRY1 and PER2 interact

The crystal structure of a complex between mouse CRY1 and mouse PER2 reveals an unexpected zinc ion stabilizing their interactions.

• Mammalian CRY/PER complexes play a key role in regulating the circadian clock.
• The crystal structure shows mPER2 wrapping around mCRY1, affecting binding sites for regulatory proteins.
• Zinc binding is essential for stabilizing the mCRY1-mPER2 interaction in living cells.
• The formation of the mCRY1/mPER2 complex may be influenced by the cell's redox state.

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