All strains were derived from Escherichia coli K12 strain NCM3722 (Soupene et al, 2003; Lyons et al, 2011) as listed in Supplementary Table 1 and detailed in Supplementary Methods. MOPS-buffered minimal media (pH 7.4) were used for cell growth as described by Neidhardt et al (1974). For carbon sources, glycerol (0.4% w/v), glucose (0.4% w/v), or 10 mM each of glucose-6 phosphate and gluconate were used. For nitrogen sources, different concentrations of NH4Cl were used as specified. All the media were filtered through 0.45 μm filters.