IDENTIFICATION OF A NOVEL OPERON IN LACTOCOCCUS-LACTIS ENCODING 3 ENZYMES FOR LACTIC-ACID SYNTHESIS - PHOSPHOFRUCTOKINASE, PYRUVATE-KINASE, AND LACTATE-DEHYDROGENASE
IDENTIFICATION OF A NOVEL OPERON IN LACTOCOCCUS-LACTIS ENCODING 3 ENZYMES FOR LACTIC-ACID SYNTHESIS - PHOSPHOFRUCTOKINASE, PYRUVATE-KINASE, AND LACTATE-DEHYDROGENASE
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DOI：
10.1128/jb.175.9.2541-2551.1993
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发表时间：
1993-05-01
影响因子：
3.2
通讯作者：
DAVIDSON, BE
中科院分区：
文献类型：
--
作者：
LLANOS, RM;HARRIS, CJ;DAVIDSON, BE
报道了在乳酸菌乳酸乳球菌中发现的一种编码磷酸果糖激酶、丙酮酸激酶和乳酸脱氢酶的新型多顺反子操纵子。操纵子中的三个基因分别被命名为pfk、pyk和ldh，分别含有340、502和325个密码子。pfk与pyk基因间的距离为87 bp，pyk与ldh基因间的距离为117 bp。 含有pfk和pyk的质粒分别赋予其宿主磷酸果糖激酶和丙酮酸激酶活性。 ldh的同一性先前通过相同的方法建立（R. M.利亚诺斯岛希利尔和B。E. Davidson，J. Bacteriol. 174：6956-6964，1992）。每个基因的前面都有一个潜在的核糖体结合位点。 操纵子以4.1-kb转录物表达。 转录物的5'和被确定为位于pfk起始密码子上游81 bp处的G核苷酸。 操纵子内的密码子使用模式是高度偏向的，具有11个未使用的氨基酸密码子。 这种程度的偏差表明操纵子高度表达。 操纵子上编码的三个蛋白是乳酸菌能量产生和乳酸合成的中心途径Embden-Meyerhoff途径中的关键酶。乳酸菌。由于这个原因，我们把这种操纵子称为las（乳酸合成）操纵子。
The discovery of a novel multicistronic operon that encodes phosphofructokinase, pyruvate kinase, and lactate dehydrogenase in the lactic acid bacterium Lactococcus lactis is reported. The three genes in the operon, designated pfk, pyk, and ldh, contain 340, 502, and 325 codons, respectively. The intergenic distances are 87 bp between pfk and pyk and 117 bp between pyk and ldh. Plasmids containing pfk and pyk conferred phosphofructokinase and pyruvate kinase activity, respectively, on their host. The identity of ldh was established previously by the same approach (R. M. Llanos, A. J. Hillier, and B. E. Davidson, J. Bacteriol. 174:6956-6964, 1992). Each of the genes is preceded by a potential ribosome binding site. The operon is expressed in a 4.1-kb transcript. The 5' and of the transcript was determined to be a G nucleotide positioned 81 bp upstream from the pfk start codon. The pattern of codon usage within the operon is highly biased, with 11 unused amino acid codons. This degree of bias suggests that the operon is highly expressed. The three proteins encoded on the operon are key enzymes in the Embden-Meyerhoff pathway, the central pathway of energy production and lactic acid synthesis in L. lactis. For this reason, we have called the operon the las (lactic acid synthesis) operon.