PORPHYRIN-ACCUMULATING MUTANTS OF ESCHERICHIA-COLI
PORPHYRIN-ACCUMULATING MUTANTS OF ESCHERICHIA-COLI
复制标题
DOI：
10.1128/jb.113.1.122-132.1973
复制
发表时间：
1973-01-01
影响因子：
3.2
通讯作者：
CHARLES, HP
中科院分区：
文献类型：
--
作者：
COX, R;CHARLES, HP
从大肠杆菌K-12 AB 1621中获得了4株能积累红色水不溶性色素的突变株（pop-1、pop-6、pop-10和pop-14）。对于每一个突变体，红色素被证明是原卟啉IX，血红素的晚期前体。突变体pop-1产生了一个次生突变体pop-1 sec-20，它积累了一种棕色的水溶性色素。棕色色素为粪卟啉III。Mujaponpop-1在细胞色素吸收光谱、过氧化氢酶活性以及在非发酵碳和能源上生长的能力方面与亲本菌株相似;因此，其产生和利用血红素的能力未受损害。根据同样的标准判断，第二个突变体pop-1 sec-20是部分血红素和呼吸缺陷的。在厌氧条件下生长，pop-1对原卟啉的积累减少了25%;在相同条件下，pop-1 sec-20不积累粪卟啉或粪卟啉原。在所有四个突变体中，引起原卟啉积累的突变都定位在E.大肠染色体在突变pop-1的情况下，突变被证明是强烈连锁的thetsx位点（12分钟）。在突变株pop-1 sec-20中，引起粪卟啉积累的第二个突变可与gallocus共转导，频率为88 - 96%。对突变体积累卟啉的机理进行了讨论。
Four mutants (pop-1, pop-6, pop-10, andpop-14) which accumulate a red water-insoluble pigment were obtained inEscherichia coliK-12 AB1621. For each mutant, the red pigment was shown to be protoporphyrin IX, a late precursor of heme. Mutagenic treatment of mutantpop-1yielded a secondary mutant,pop-1 sec-20, which accumulated a brown water-soluble pigment. The brown pigment was shown to be coproporphyrin III. Mutantpop-1resembled the parental strain in its cytochrome absorption spectrum, catalase activity, and ability to grow on nonfermentable carbon and energy sources; therefore, its ability to produce and utilize heme was unimpaired. Judged on the same criteria, the secondary mutant,pop-1 sec-20, was partially heme and respiratory deficient. Growth in anaerobic conditions decreased by 25% the accumulation of protoporphyrin bypop-1;under the same conditions,pop-1 sec-20did not accumulate coproporphyrin or coproporphyrinogen. The mutations causing protoporphyrin accumulation in all fourpopmutants were found to map in thelactopurE(10–13 min) region of theE. colichromosome. In the case of mutantpop-1, the mutation was shown to be strongly linked to thetsxlocus (12 min). In mutantpop-1 sec-20, the second mutation causing coproporphyrin accumulation was co-transducible with thegallocus at a frequency of 88 to 96%. The mechanism of porphyrin accumulation by the mutants is discussed.