Effect of gene amplifications in porphyrin pathway on heme biosynthesis in a recombinant Escherichia coli

J Microbiol Biotechnol. 2013 May;23(5):668-73. doi: 10.4014/jmb.1302.02022.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biosynthetic Pathways
  • Escherichia coli / enzymology
  • Escherichia coli / genetics*
  • Escherichia coli / metabolism*
  • Escherichia coli Proteins / genetics*
  • Escherichia coli Proteins / metabolism
  • Gene Amplification*
  • Heme / biosynthesis*
  • Hydroxymethylbilane Synthase / genetics
  • Hydroxymethylbilane Synthase / metabolism
  • Malate Dehydrogenase / genetics
  • Malate Dehydrogenase / metabolism
  • Porphyrins / metabolism*
  • Uroporphyrinogen III Synthetase / genetics
  • Uroporphyrinogen III Synthetase / metabolism

Substances

  • Escherichia coli Proteins
  • Porphyrins
  • Heme
  • Malate Dehydrogenase
  • malate dehydrogenase (oxaloacetate-decarboxylating) (NADP+)
  • Hydroxymethylbilane Synthase
  • Uroporphyrinogen III Synthetase