Fig 3.

Indigoidine production in the mlbpA strain. WT, wild-type strain; mlbpA, mlbpA strains. The translated amino acid sequences are indicated above the corresponding nucleotide sequences. Mutated bases are shown in bold, and asterisks indicate stop codons. (A) Structural organization of LbpA and sequence alignment of the lbpA locus edited by pTarget-lbpA. The functional domains are shown: A, adenylation; Ox, oxidation; T, thiolation; TE, thioesterase. The PAM sequence is shown in the box. The expected editing site is shown by the nucleotide number relative to the PAM sequence. The translated amino acid sequences are indicated above the corresponding nucleotide sequences. A mutated base is shown in bold, and asterisks indicate stop codons. (B) Indigoidine production of the mlbpA strain grown on solid cultivation (top plate) and in liquid cultivation (bottom flask). The top panel shows a representative Sanger sequencing chromatogram of the target region with the predicted C-to-T mutation. A mutated base is indicated by a black arrow. For solid cultivation, each strain was cultivated on ISP medium two and incubated for 2 days at 28°C. The plate was photographed from the bottom. For liquid cultivation, each strain was inoculated into liquid medium B and incubated at 28°C for 7 h. IM-2-C₅ was added at the final concentration of 1.2-ng/mL medium, followed by incubation for an additional 2 h.