To date, the metabolic mutations associated with cancer are found mainly in isocitrate dehydrogenase (IDH), succinate dehydrogenase (SDH), and fumarate hydratase (FH).
The remaining 6 genotypes are present at very low frequencies, close to their metabolic mutation-selection equilibria.
Control experiments showed that none of the metabolic mutations affect viability of DnaE WT cells at high temperature in LB.
Metabolic mutations carried by strains provided by different laboratories were transferred in the TF8A context using transformation and appropriate marker selection DGRM14-177, 27 337–36, 36 and 37).
Most metabolic mutations (15/19) were not suppressive as they did not restore cell viability on plates at high temperature (Fig. 2, yellow boxes).
The presence of the metabolic mutations and of the fusion were verified by analyzing cell growth in LB at 37°C and by PCR, respectively.
First, the genetic transfer of metabolic mutations (pgkEP, pgm8, pgmIP or pykAJP, labeled by a genetic marker) into parental dnaE(Ts) strains led to Tr transformants.
To measure the effect of metabolic mutations on carbon flux polarity, competent cells of the GM1514 strain that contains lacZ downstream from the gapB promoter at the amyE locus were transformed with the total DNA extracted from strains carrying metabolic mutations (168 Pgi::spc, 501 77, GM1501, GTD040 and DGRM18, 25).
Surprisingly, rather than occurring in functions related to DNA metabolism, they fell into four metabolic genes (pgk, pgm, eno and pykA) ensuring the terminal reactions of glycolysis (Fig. 1A, the suppressed strains and metabolic mutations are listed Table 2).
