title: 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.
authors: Department of Biotechnology, The Catholic University of Korea, Bucheon, Gyeonggi 420-742, Korea.
authors: Min Ju
authors: MJ
authors: Lee
authors: Hye-Jung
authors: HJ
authors: Kim
authors: Ju-Young
authors: JY
authors: Lee
authors: An Sung
authors: AS
authors: Kwon
authors: Soo Youn
authors: SY
authors: Jun
authors: Sang Hyeon
authors: SH
authors: Kang
authors: Pil
authors: P
authors: Kim
mesh_terms: D053898:Biosynthetic Pathways; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000235:genetics* / Q000378:metabolism; D005784:Gene Amplification; D006418:Heme / Q000096:biosynthesis*; D011163:Hydroxymethylbilane Synthase / Q000235:genetics / Q000378:metabolism; D008291:Malate Dehydrogenase / Q000235:genetics / Q000378:metabolism; D011166:Porphyrins / Q000378:metabolism*; D014576:Uroporphyrinogen III Synthetase / Q000235:genetics / Q000378:metabolism
chemical_list: D029968:Escherichia coli Proteins; D011166:Porphyrins; D006418:Heme; D008291:Malate Dehydrogenase; C031917:malate dehydrogenase (oxaloacetate-decarboxylating) (NADP+); D011163:Hydroxymethylbilane Synthase; D014576:Uroporphyrinogen III Synthetase