(A) Schematic of the human PGBD5 protein with its C-terminal transposase homology domain, as indicated. (B) Schematic of synthetic transposon substrates used for DNA transposition assays, including transposons with mutant ITR marked by triangles in red, and transposons lacking ITRs marked in blue. (C) Representative photographs of crystal violet-stained colonies obtained after G418 selection of HEK293 cells co-transfected with the transposon reporter plasmid along with transposase cDNA expression vectors. (D) Quantification of G418-selection clonogenic assays, demonstrating the integration activities of GFP-PGBD5, PGBD5 N-terminus, T. ni. piggyBac, and green fluorescent protein (GFP) control (GFP-PGBD5 vs GFP; p = 0.00031). (E) Quantification of genomic transposon integration using quantitative PCR of GFP-PGBD5 and GFP expressing cells using intact (black), mutant (red), and deleted (blue) ITR-containing transposon reporters (intact vs mutant ITR; p = 0.00011). Error bars represent standard errors of the mean of 3 biologic replicates.