Non-iron porphyrins cause tumbling to blue light by an Escherichia coli mutant defective in hemG.
Non-iron porphyrins cause tumbling to blue light by an Escherichia coli mutant defective in hemG.
复制标题
非铁卟啉会导致 hemG 缺陷的大肠杆菌突变体转变成蓝光。
DOI：
10.1073/pnas.93.6.2459
复制
发表时间：
1996
影响因子：
11.1
通讯作者：
Adler,J
中科院分区：
文献类型：
--
作者：
Yang,H;Sasarman,A;Inokuchi,H;Adler,J
以前，我们表明，大肠杆菌hemH突变体，在血红素合成的最终步骤，亚铁螯合酶缺陷，是略好于100倍以上的敏感性比其野生型亲本翻滚蓝光。在这里，我们探讨的影响hemG突变体，缺陷的倒数第二步，原卟啉原氧化酶。我们发现，与野生型亲本相比，hemG突变体对蓝光的敏感性也要好100倍以上。hemG或hemH突变体中积累的非铁卟啉的量是野生型的100倍以上。这些积累的卟啉的性质进行了描述。当存在血红素时，如野生型中那样，非铁（非血红素）卟啉保持在相对较低的浓度，并且不会出现对hemG或hemH有效的强度的蓝光。翻滚到光的功能是最有可能让逃离强光的杀伤力。
Previously we showed that an Escherichia coli hemH mutant, defective in the ultimate step of heme synthesis, ferrochelatase, is somewhat better than 100-fold more sensitive than its wild-type parent in tumbling to blue light. Here we explore the effect of a hemG mutant, defective in the penultimate step, protoporphyrinogen oxidase. We found that a hemG mutant also is somewhat better than 100-fold more sensitive in tumbling to blue light compared to its wild-type parent. The amount of non-iron porphyrins accumulated in hemG or hemH mutants was more than 100-fold greater than in wild type. The nature of these accumulated porphyrins is described. When heme was present, as in the wild type, the non-iron (non-heme) porphyrins were maintained at a relatively low concentration and tumbling to blue light at an intensity effective for hemG or hemH did not occur. The function of tumbling to light is most likely to allow escape from the lethality of intense light.