REPAIR OF IRRADIATED TRANSFORMING DEOXYRIBONUCLEIC ACID IN WILD TYPE AND A RADIATION-SENSITIVE MUTANT OF MICROCOCCUS-RADIODURANS
REPAIR OF IRRADIATED TRANSFORMING DEOXYRIBONUCLEIC ACID IN WILD TYPE AND A RADIATION-SENSITIVE MUTANT OF MICROCOCCUS-RADIODURANS
复制标题
DOI：
10.1128/jb.105.3.976-983.1971
复制
发表时间：
1971-01-01
影响因子：
3.2
通讯作者：
MATTINGLY, A
中科院分区：
文献类型：
--
作者：
MOSELEY, BEB;MATTINGLY, A
本文研究了耐辐射微球菌（Micrococcusradiodurans）的野生型和辐射敏感突变体在辐射转化脱氧核糖核酸（DNA）中的生物活性存活情况。在突变体中，用未辐照的DNA转化的频率较低，与突变体对辐射的敏感性增加的程度大致相同。然而，在野生型和突变体中，被掺入细菌基因组中的辐射DNA被修复到与随着辐射剂量增加而丧失转化活性所确定的相同程度。这适用于电离辐射或紫外线（UV）辐射照射的DNA。紫外线照射后的生物活性的失活率在任何测试的DNA制备物中是相同的。对于电离辐射，失活率变化高达40倍，这取决于所使用的DNA制备，但对于任何一种制备是相同的，无论是在野生型或辐射敏感突变体中测定。当受体细菌在转化前立即用电离辐射或UV辐射照射时，用未照射的DNA转化的频率下降，在敏感突变体的情况下迅速地呈指数下降，但在野生型中以更复杂的方式下降。无论是在未照射的宿主还是在照射的宿主中，电离辐射照射的DNA的修复都大致相同。因此，照射宿主减少了DNA的整合，但没有减少其修复。
The survival of biological activity in irradiated transforming deoxyribonucleic acid (DNA) has been assayed in the wild type and a radiation-sensitive mutant ofMicrococcus radiodurans. The frequency of transformation with unirradiated DNA was lower in the mutant to about the same extent as the mutant's increased sensitivity to radiation. However, in both the wild type and the mutant, the irradiated DNA that was incorporated into the bacterial genome was repaired to the same extent as determined by the loss of transforming activity with increasing radiation dose. This applied to DNA irradiated either with ionizing or ultraviolet (UV) radiation. The rate of inactivation of biological activity after UV radiation was the same in any of the DNA preparations tested. For ionizing radiation, the rate of inactivation varied up to 40-fold, depending on the DNA preparation used, but for any one preparation was the same whether assayed in the wild type or the radiation-sensitive mutant. When recipient bacteria were irradiated with ionizing or UV radiation immediately before transformation, the frequency of transformation with unirradiated DNA fell, rapidly and exponentially in the case of the sensitive mutant but in a more complicated fashion in the wild type. The repair of DNA irradiated with ionizing radiation was approximately the same whether assayed in unirradiated or irradiated hosts. Thus, irradiation of the host reduced the integration of DNA but not its repair.