Figure 2.

ERF superfamily protein Rec2 exhibits improved recombination frequencies after electroporation with rpsL‐directed mutagenic oligonucleotide SR. Pseudomonas putida EM42 strains containing pSEVA258 and pSEVA258‐recX constructs were induced with 3MB before electroporation with mutagenic oligo SR. After overnight recovery in TB, culture dilutions were plated on LB and LB‐Sm solid media. Colony counts were determined, and correct SR‐mediated changes were checked by amplifying and sequencing the rpsL gene from 5 to 10 Sm^R clones associated with each experiment (see Experimental procedures for further details). Recombineering efficiency was calculated as the number of Sm^R mutants per 10⁹ cells. Column graphs of the resulting data were generated with graphpad prism. Column values represent mean recombineering frequencies for each experimental condition; standard error (SE) bars are also shown. Each data set represents at least two independent experimental replicates. Recombineering values are shown on a linear scale to facilitate frequency comparison. Absolute frequency values (mutants per viable cell) are shown above each column. Controls 258⁺ and 258⁻ indicate Sm^R colonies arising from P. putida EM42 (pSEVA258) cells electroporated or not, respectively, with the mutagenic oligonucleotide.