Kinetic framework for full-length and truncated pre-crRNA variants. (A) Processing reaction of pre-crRNA by Cas12a. For further information on the chemical mechanism of pre-crRNA cleavage, see Swarts et al. (2017). (B) Sequence of the full-length pre-crRNA (pre-crRNA−34:+24), with the nucleotide numbering convention from Swarts et al. (2017). The repeat sequence is divided conceptually into a leader sequence (blue) and pseudoknot (orange). The guide sequence is green. Deletion constructs used herein are schematized below the pre-crRNA sequence. (C) Binding, dissociation, and cleavage steps and rate constants of the full-length pre-crRNA and the truncated forms tested herein. Binding and dissociation rate constants for the corresponding mature crRNA products are shown at the right. Uncertainties were typically 10%−30% and are listed in Table 1.
