Extended Data Fig. 1: Ortholog screening of IscB family, related to Fig. 1.

(A) Experimental traversal of the IscB phylogenetic tree to identify IscB orthologs active for human genome editing. Initial set of 6 tested IscBs shown on left. Set 1 of phylogenetically diverse IscBs/II-D Cas9s shown in middle. Set 2 of mainly larger IscBs with potential REC inserts shown on right. (B) TAMs of active IscB proteins determined by in vitro cleavage assays. All the protein sequences and accession of source contigs are listed in Table S1. (C) TAM wheel representation of OrufIscB TAM. All motifs adding up to 5% or more of cleaved TAMs are listed to the right. Constituents of each relevant motif are labeled around the circumference of the TAM wheel. (D) Schematic of the ortholog screening in HEK293FT cells (results shown in Fig. 1C). (E) Zoomed in y-axis representation of Indel formation mediated by TbaIscB with individual guides in HEK293FT cells displayed in Fig. 1D. Data are presented as mean +/- SD, n = 4 replicate transfections. (F) Indel formation mediated by WT OrufIscB with individual guides in HEK293FT cells. Data are presented as mean +/- SD, n = 4 replicate transfections.