Construction of Escherichia coli strains producing L-serine from glucose
Construction of Escherichia coli strains producing L-serine from glucose
复制标题
葡萄糖产L-丝氨酸大肠杆菌菌株的构建
DOI：
10.1007/s10529-012-0937-0
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发表时间：
2012-08-01
影响因子：
2.7
通讯作者：
Lu, Fu-Ping
中科院分区：
文献类型：
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作者：
Li, Yu;Chen, Gu-Kui;Lu, Fu-Ping
l-丝氨酸通常由甘氨酸产生。我们对大肠杆菌进行了基因工程改造，使其在细胞内从葡萄糖中产生l-丝氨酸。d-3-磷酸甘油酸脱氢酶（PGDH，EC 1.1.1.95）在E.大肠杆菌催化L-丝氨酸形成的第一个关键步骤，但被L-丝氨酸抑制。为了克服这种反馈抑制，PGDH的His（344）和Asn（346）残基都被转化为丙氨酸，并且突变的PGDH（PGDH（dr））变得对l-丝氨酸不敏感。然而，PGDH（dr）的过表达并没有显著增加l-丝氨酸的积累，但是，当l-丝氨酸脱氨酶基因（sdaA、sdaB和tdcG）缺失，丝氨酸积累：（1）sdaA缺失产生高达0.03 mmol l-丝氨酸/g;（2）sdaA和sdaB均缺失，l-丝氨酸积累高达0.09 mmol/g;（3）缺失sdaA、sdaB和tdcG后，L-丝氨酸的含量为0.13 mmol/g细胞干重。
l-Serine is usually produced from glycine. We have genetically engineered Escherichia coli to produce l-serine from glucose intracellularly. d-3-Phosphoglycerate dehydrogenase (PGDH, EC 1.1.1.95) in E. coli catalyzes the first committed step in l-serine formation but is inhibited by l-serine. To overcome this feedback inhibition, both the His(344) and Asn(346) residues of PGDH were converted to alanine and the mutated PGDH (PGDH(dr)) became insensitive to l-serine. However, overexpression of PGDH(dr) gave no significant increase of l-serine accumulation but, when l-serine deaminase genes (sdaA, sdaB and tdcG) were deleted, serine accumulated: (1) deletion of sdaA gave up to 0.03 mmol l-serine/g; (2) deletion of both sdaA and sdaB accumulated l-serine up to 0.09 mmol/g; and (3) deletion of sdaA, sdaB and tdcG gave up to 0.13 mmol l-serine/g cell dry wt.