Effect of Gene Amplifications in Porphyrin Pathway on Heme Biosynthesis in a Recombinant Escherichia coli

Abstract

A recombinant E. coli co-expressing ALA synthase (hemA), NADP-dependent malic enzyme (maeB), and dicarboxylic acid transporter (dctA) was reported to synthesize porphyrin derivatives including iron-containing heme. To enhance the synthesis of bacterial heme, five genes of the porphyrin biosynthetic pathway [pantothenate kinase (coaA), ALA dehydratase (hemB), 1-hydroxymethylbilane synthase (hemC), uroporphyrinogen III synthase (hemD), and uroporphyrinogen III decarboxylase (hemE)] were amplified in the recombinant E. coli co-expressing hemA-maeB-dctA. Pantothenate kinase expression enabled the recombinant E. coli to accumulate intracellular CoA. Intracellular ALA was the most enhanced by uroporphyrinogen III synthase expression, porphobilinogen by ALA dehydratase expression, and uroporphyrin and coproporphyrin by 1- hydroxymethylbilane synthase expression. The strain coexpressing coaA, hemA, maeB, and dctA produced heme of 0.49 micromol/g-DCW, which was twice as much from the strain without coaA expression. Further strain improvement for the porphyrin derivatives is discussed based on the results.

Optimization of the heme biosynthesis pathway for the production of 5-aminolevulinic acid in Escherichia coli

“…5 ), which are in agreement with ALA production ( Fig. 2 ) and the results from the C4 pathway 29 . These findings suggested that hemB , hemG , hemH and hemD have central regulatory roles in the heme biosynthesis pathway and their transcriptional levels are tightly regulated.…”

Prokaryotic type III pantothenate kinase enhances coenzyme A biosynthesis in <i>Escherichia coli</i>

“…On the other hand, Vadali and coworkers (2004a) successfully increased the intracellular CoA pool by expressing E. coli pantothenate kinase from a high-copy number plasmid. This strategy was highly effective in producing useful compounds such as isoamyl acetate (Vadali et al, 2004b), succinate (Lin et al, 2004), antibiotics (Mandakh et al, 2010), and porphyrin (Lee et al, 2013).…”

Identification of the Regulon of AphB and Its Essential Roles in LuxR and Exotoxin Asp Expression in the Pathogen Vibrio alginolyticus

“…The product of EPGS_03654 (metH) is a vitamin B 12 methyltransferase, which plays an important role in the biosynthesis of methionine (28). In addition, the ChIP-seq data ( Table 2) also indicated that AphB could regulate heme biosynthesis (29), sodium potassium pumps, and amino acid metabolism (Fig. 8).…”