Fig. 1
From: Engineering Escherichia coli for efficient assembly of heme proteins
Heme biosynthetic pathways in K. phaffii and E. coli. The pathways emphasized in gray, blue, yellow and orange indicate the modules of tricarboxylic acid (TCA) cycle, 5-aminolevulinate (Module 1), tetrapyrrole (Module 2) and downstream heme biosynthesis pathway (Module 3), respectively. The corresponding metabolic genes indicated in blue and red were overexpressed in K. phaffii and E. coli recombinants, respectively, for promoting heme synthesis. gltX, glutamyl-tRNA synthetase gene; hemA, glutamyl-tRNA reductase gene; hemL, glutamate-1-semialdehyde-2,1-aminomutase gene; hem1, 5-aminolevulinate synthase gene; hemB (hem2), delta-aminolevulinic acid dehydratase gene; hemC (hem3), porphobilinogen deaminase gene; hemD (hem4), uroporphyrinogen-III synthase gene; hemE (hem12), uroporphyrinogen decarboxylase gene; hemF (hem13), coproporphyrinogen-III oxidase gene; hemG (hem14), protoporphyrinogen IX dehydrogenase gene; hemH (hem15), ferrochelatase gene