Shin Jeong-Ah, Kwon Yeong Deok, Kwon Oh-Hee, Lee Heung Shick, Kim Pil
Department of Biotechnology, The Catholic University of Korea, Bucheon, Gyunggi 420-743, Korea.
J Microbiol Biotechnol. 2007 Sep;17(9):1579-84.
5-aminolevulinate (ALA) synthase (E.C. 2.3.1.37), which mediates the pyridoxal phosphate-dependent condensation of glycine and succinyl-CoA, encoded by the Rhodobacter sphaeroides hemA gene, enables Escherichia coli strains to produce ALA at a low level. To study the effect of the enhanced C4 metabolism of E. coli on ALA biosynthesis, NADP-dependent malic enzyme (maeB, E.C. 1.1.1.40) was coexpressed with ALA synthase in E. coli. The concentration of ALA was two times greater in cells coexpressing maeB and hemA than in cells expressing hemA alone under anaerobic conditions with medium containing glucose and glycine. Enhanced ALA synthase activity via coupled expression of hemA and maeB may lead to metabolic engineering of E. coli capable of large-scale ALA production.
5-氨基乙酰丙酸（ALA）合酶（E.C. 2.3.1.37）介导甘氨酸和琥珀酰辅酶A的磷酸吡哆醛依赖性缩合反应，由球形红杆菌hemA基因编码，可使大肠杆菌菌株低水平产生ALA。为研究大肠杆菌增强的C4代谢对ALA生物合成的影响，将依赖NADP的苹果酸酶（maeB，E.C. 1.1.1.40）与ALA合酶在大肠杆菌中共表达。在含有葡萄糖和甘氨酸的培养基厌氧条件下，共表达maeB和hemA的细胞中ALA浓度比单独表达hemA的细胞高两倍。通过hemA和maeB的偶联表达增强ALA合酶活性，可能会导致能够大规模生产ALA的大肠杆菌代谢工程。
