Fig. 3: Biosynthesis of K. oxytoca pyrazines.
From: Mucosal sugars delineate pyrazine vs pyrazinone autoinducer signaling in Klebsiella oxytoca
a Proposed biosynthesis of K. oxytoca pyrazines. Molecular moieties are color coded to delineate chemical precursors. b Genetic architecture of the pyr operon in K. oxytoca. c XC-MS-based volcano plot analysis of chemical features differentially regulated between wildtype and ∆pyr K. oxytoca strains grown in M9 medium supplemented with D-galactose. Pyrazines 5–9 (TALA-AA-Py, TALA-Py, PALA-AA-Py, PALA-TALA-Py, and PALA-Py, respectively) and precursors 12 (PALA) and 13 (TALA) are marked. d 310 nm absorbance chromatograms of wildtype K. oxytoca, ∆pyr K. oxytoca, and medium control samples. e HPLC-QTOF-MS extracted ion chromatograms of 12 and 13 in wildtype K. oxytoca, ∆pyr K. oxytoca, and medium control samples. f HPLC-QTOF-MS extracted ion chromatograms of compounds 6, 8, and 9 from heterologous expression of the K. oxytoca pyr gene in E. coli BL21(DE3). For panels d, e, and f, representative traces of three biological replicates are shown (n = 3). For panel c statistical analysis was performed through a paired Welch t-test.
