Fig. 1: Characterization of QS systems from both Gram-negative and -positive bacterial species. | Nature Communications

Fig. 1: Characterization of QS systems from both Gram-negative and -positive bacterial species.

From: Developing a pathway-independent and full-autonomous global resource allocation strategy to dynamically switching phenotypic states

Fig. 1

a Schematic of a modular three-plasmid system, including a signal plasmid (Ps), an regulator plasmid (Pr), and a reporter plasmid. b Validating the function of each QS system using native promoters for QS component expression. c Fusing QS components with GFP to measure translational output directly. Pbd, native promoter of AgrBD; Pac, native promoter of AgrAC; Pr, native promoter of PrgX; Pc, native promoter of CcfA; Ptrc, constitutive trc promoter. d Validating the function of each QS system using constitutive Ptrc promoters for QS component expression. The function of each QS system was validated by comparing normalized GFP fluorescence from strains harboring plasmids of Ps, Pa, and Pp to strains only harboring Pp. All fluorescence measurements were normalized by dividing measured fluorescence values by the OD600 of that well to conduct a per-cell measurement. The recombinant strains were grown in 25 mL of MOPS medium at 30 °C with 220 rpm orbital shaking. Cell fluorescence and cell density (OD600) were measured after 30 h of culture on a Cytation 3 imaging reader system (BioTek, Winooski, USA). (−) indicated the wild type strain E. coli MG1655 with corresponding empty plasmids as the negative control. Values are shown as mean ± SD (n = 3 biological replicates). Source data are available in the Source data file.

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