Fig. 1

Metabolic pathway for isoprene production in engineered E. coli. a Isoprene was catalyzed by IspS from DMAPP. DAMPP was synthesized through the MVA pathway. The precursors of the MVA pathway, Ac-CoA was synthesized through the glycolysis pathway from glucose. Abbreviations: acetyl-CoA (Ac-CoA); acetoacetyl-CoA (AcAc-CoA); 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA); mevalonate (MVA); mevalonate-5-phosphate (MVAP); mevalonate-5-pyrophosphate (MVAPP); isopentenyl diphosphate (IPP); dimethylallyl diphosphate (DMAPP). b The constructed two plasmids overexpressing genes of the MVA pathway and IspS. The promoters, RBS sequences and the genes were illustrated. The red arrow indicated the key enzyme that was modified in this research. The red oval indicated the RBS sequence that was optimized to increase the T.I.R. value. The blue oval indicated the RBS sequence that was optimized to reduce the T.I.R. value