FIG 3.
Branching-enzyme and debranching-enzyme mutagenesis. (A) Map showing the site of amino-terminal truncation mutagenesis. (B) Gel electrophoresis showing DNA fragments amplified by PCR indicate complete segregation of the modified genes in the Δ97 and Δ112 mutant strains. (C) Map showing the double homologous recombination replacement of the debranching enzyme slr0237 with PCC8801_1045. us, upstream region; ds, downstream region; nt, nucleotide, SpR, spectinomycin resistance gene; ×, location of double homologous crossover. Arrowheads indicate the locations where the PCR primers used for verification of gene mutagenesis were annealed.