Isolation of a complex formed between acinetobacter baumannii hema and heml, key enzymes of tetrapyrroles biosynthesis
Plants, algae and most bacteria synthesize 5-aminolevulinic acid (ALA), the universal precursor of tetrapyrroles such as heme, chlorophyll and coenzyme B12, by a two-step transformation involving the NADPH-dependent glutamyl-tRNA reductase (HemA), which reduces tRNA-bound glutamate to glutamate-1-semialdehyde (GSA), and the pyridoxamine 5'-phosphate-dependent glutamate-1-semialdehyde-2,1-aminomutase (HemL), responsible for the isomerization of GSA into ALA.