Fig. 3
Biosynthesis and structures of lipids in E. coli. a The biosynthesis pathway of PE, PG and CL in E. coli. The red colored genes are critical for the different biosynthesis pathways for PE, PG and CL. b Structures of PE, PG and CL. The blue colored parts of the structural formula highlight the differences of PE, PG and CL. c Structures of less toxic LPS for E. coli. PS-Kdo2-lipid A is the wild-type LPS in E. coli K-12, PS-MPLA is the less toxic LPS structure after the modification of LpxE deriving Francisella novicida in E. coli K-12, PS-pentaacyl-MPLA is the least toxic LPS structure after FLpxE expression and LpxM removal in E. coli K-12. The key groups and enzymes are colored in red or blue