Fig. 3

Maturation of BLP by extracellular proteases of B. subtilis. The B. subtilis Dpr9 strain and the parental strain 168 were transformed with pHY300PLK (empty vector) or pHY-BLP02. Cells were grown at 30 °C for 72 h in modified 2 × L-Mal medium. A SDS-PAGE analysis of culture supernatants. The supernatants were diluted two-fold with SDS reducing buffer. Five microliters of each sample were applied to SDS-PAGE. The expression plasmids and hosts are indicated above and below the image, respectively. The black arrow indicates the position of mature BLP. The red arrows indicate the positions of unprocessed or partially cleaved forms of pro-BLP, and their N-terminal sequences are shown. B Pentaglycine cleavage activity assay of culture supernatants using the pentaglycine-containing FRET substrate FRET-GGGGG. The results presented are the means of three individual experiments. Error bars represent the standard errors of the means. C Amino acid sequence of BLP encoded by pHY-BLP02. The signal sequence is underlined with a dotted line, and the pro sequences is underlined with a straight line. The N-terminal sequences detected in the culture supernatant of Dpr9 strain are shown in red bold