THE USE OF SUICIDE SUBSTRATES TO SELECT MUTANTS OF ESCHERICHIA-COLI LACKING ENZYMES OF ALCOHOL FERMENTATION
THE USE OF SUICIDE SUBSTRATES TO SELECT MUTANTS OF ESCHERICHIA-COLI LACKING ENZYMES OF ALCOHOL FERMENTATION
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DOI：
10.1007/bf00338087
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发表时间：
1986-01-01
期刊：
影响因子：
--
通讯作者：
CLARK, DP
中科院分区：
文献类型：
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作者：
CUNNINGHAM, PR;CLARK, DP
选择了对氯乙醇或氯乙醛具有抗性的大肠杆菌突变体。发现这样的突变体缺乏发酵辅酶A（CoA）连接的乙醛脱氢酶活性。大多数也缺乏相关的发酵酶乙醇脱氢酶。这两种类型的突变体，那些缺乏乙醛脱氢酶单独或缺乏两种酶，定位接近调节adhC基因在27分钟的E。大肠杆菌遗传图谱。先前描述的acd突变体，缺乏乙醛脱氢酶，并在63分钟映射被证明是多效性的，影响呼吸和各种底物上的生长。因此，乙醛和乙醇脱氢酶的结构基因似乎都位于adhCE操纵子中。这种解释得到了证实，分离的温度敏感性氯乙酰丙酮抗性突变体，其中一些产生热不稳定的乙醛脱氢酶和乙醇脱氢酶，也被发现在ADH基因座的地图。回复突变分析表明，缺失一种或两种酶的突变体携带单一突变。adh区域中的基因顺序通过三个点杂交确定为trp-zch：：Tn 10-adh-galU-bglY-tyrT-chlC。
Mutants of Escherichia coli resistant to chloroethanol or to chloroacetaldehyde were selected. Such mutants were found to lack the fermentative coenzyme A (CoA) linked acetaldehyde dehydrogenase activity. Most also lacked the associated fermentative enzyme alcohol dehydrogenase. Both types of mutants, those lacking acetaldehyde dehydrogenase alone or lacking both enzymes, mapped close to the regulatory adhC gene at 27 min on the E. coli genetic map. The previously described acd mutants which lack acetaldehyde dehydrogenase and which map at 63 min were shown to be pleiotropic, affecting respiration and growth on a variety of substrates. It therefore seems likely that the structural genes for both the acetaldehyde and alcohol dehydrogenases lie in the adhCE operon. This interpretation was confirmed by the isolation of temperature sensitive chloracetaldehyde-resistant mutants, some of which produced thermolabile acetaldehyde dehydrogenase and alcohol dehydrogenase and were also found to map at the adh locus. Reversion analysis indicated that mutants lacking one or both enzymes carried single mutations. The gene order in the adh region was determined by three point crosses to be trp-zch::Tn10-adh-galU-bglY-tyrT-chlC.