Adaptive Laboratory Evolution of Glycolytic Metabolism in Glucokinase Deficient Strains of Escherichia coli

A key step in metabolic pathway evolution is the recruitment of promiscuous enzymes to perform new functions. Despite the recognition that promiscuity is widespread in biology, factors dictating the preferential recruitment of one promiscuous enzyme over other candidates are unknown. Escherichia coli contains four sugar kinases that are candidates for recruitment when the native glucokinase machinery is deleted: allokinase (AlsK), manno(fructo)kinase (Mak), N-acetylmannosamine kinase (NanK) and N-acetylglucosamine kinase (NagK). We performed adaptive evolution of a glucokinase-deficient E. coli strain to restore glycolytic metabolism. Whole genome resequencing revealed which latent glucokinase was recruited and by what mechanism.