紫外线照射的盘基网柄菌中核脱氧核糖核酸嘧啶二聚体的切除
Excision of pyrimidine dimers from nuclear deoxyribonucleic acid in ultraviolet-irradiated Dictyostelium discoideum.
作者信息
Clark J M, Deering R A
机构信息
Biophysics Program, Pennsylvania State University, University Park 16802.
出版信息
Mol Cell Biol. 1981 Feb;1(2):121-7. doi: 10.1128/mcb.1.2.121-127.1981.
A sensitive endonuclease assay was used to study the fate of pyrimidine dimers introduced by ultraviolet irradiation into the nuclear deoxyribonucleic acid of the cellular slime mold Dictyostelium discoideum. Analysis of the frequency of T4 endonuclease V-induced single-strand breaks by alkaline sucrose gradient sedimentation showed that strain NC4 (rad+) removed greater than 98% of the dimers induced by irradiation at 40 J/m2 (254 nm) within 215 min after irradiation. HPS104 (radC44), a mutant sensitive to ultraviolet irradiation, removed 91% under these conditions, although at a significantly slower rate than NC4: only 8% were removed during the 10- to 15-min period immediately after irradiation, whereas NC4 excised 64% during this interval. HPS104 thus appears to be deficient in the activity(ies) responsible for rapidly incising ultraviolet-irradiated nuclear deoxyribonucleic acid at the sites of pyrimidine dimers.
采用一种灵敏的核酸内切酶测定法来研究紫外线照射引入到细胞黏菌盘基网柄菌细胞核脱氧核糖核酸中的嘧啶二聚体的命运。通过碱性蔗糖梯度沉降分析T4核酸内切酶V诱导的单链断裂频率表明，菌株NC4（rad +）在照射后215分钟内可去除40 J/m2（254 nm）照射诱导的超过98%的二聚体。对紫外线照射敏感的突变体HPS104（radC44）在这些条件下去除了91%，尽管其速率明显慢于NC4：在照射后紧接着的10至15分钟内仅去除了8%，而NC4在此时间段内切除了64%。因此，HPS104似乎在负责在嘧啶二聚体位点快速切割紫外线照射的细胞核脱氧核糖核酸的活性方面存在缺陷。
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