Fig. 5

Site-directed mutagenesis on the M106 residue of the CvPHBH. The molecular structure model was visualized using the PyMOL Molecular Graphics System (Version 2.0, Schrödinger, LLC, New York, NY, USA). A The location of Y161 and D357 in the three-dimensional structure model of CvPHBH. Purple stick represents the Y161 and D357 residues. Green and sky-blue stick represents 4-aminobenzoic acid (4-ABA) and FAD, respectively. B Interaction of D357 and R179 in the crystal structure of PaPHBH (PDB ID: 1IUT). Purple and yellow sticks represent the designated amino acids of chain A and chain B, respectively. The dotted line represents hydrogen bonds. C The location of M106 in the three-dimensional structure. Purple stick represents the Y161 and M106 residues. D The results of HPLC analysis of the culture supernatants of Corynebacterium glutamicum strains expressing the CvPHBH mutants. White and gray colored bars indicate the concentration of 4-ABA and 4-amino-3-hydroxybenzoic acid (4,3-AHBA), respectively. Data are represented as mean ± standard deviation of biological replicates (n = 6). Yellow circles indicate the mean percentage of 4,3-AHBA. The horizontal axis indicates the strains of interest expressing CvPHBH mutants. WT: wild type