Circular permutation of mito-ZifCY1 dramatically increases its dynamic range. a) The N-and C-termini of cpV FPs are relocated to 5 different loops of the original Venus FP at the amino acid positions 49, 157, 173, 195, and 229. b) The average R of the unbound and bound sensors expressed in at least 10 cells from 2 or more independent experiments, acquired using identical exposure times, are summarized. c) High dynamic range sensors report lower fractional saturation.