FIG 1.

PEP, but not 2PL, stimulates DH-F₄₂₀-0 synthesis in M. smegmatis cell lysates. (A) Two-dimensional (2D) structures of PEP and 2PL demonstrating the difference (double bond or single bond) in bonding between carbon 2 and 3. (B) Fluorescence emission detection chromatogram from HPLC of M. smegmatis lysates spiked with either 2PL or PEP or an unspiked control. Synthesis of a species with characteristic F₄₂₀ fluorescence (excitation, 420 nm; emission, 480 nm) corresponding to F₄₂₀-0 from the purified standard was detected only in the PEP-spiked lysate. The appearance of this F₄₂₀-0-like species coincided with a decrease in the presence of Fo, suggesting that PEP is the precursor for F₄₂₀ synthesis in M. smegmatis in cells. F₄₂₀-1 in the standard corresponds to F₄₂₀ with a single glutamate moiety.