(A) Domain overview of full-length A. thaliana CRY1 (top) and the synthetic CRY-microProtein that contains only the PH domain required for dimerisation. (B) The CRY-microProtein disrupts the formation of an active CRY homodimer by forming an inactive CRY-microProtein/CRY heterodimer, thereby sequestering the CRY monomers.