Overbye K M, Margolin P
J Bacteriol. 1981 Apr;146(1):170-8. doi: 10.1128/jb.146.1.170-178.1981.
Salmonella typhimurium strains with supX mutations are more sensitive than wild type to killing by ultraviolet (UV) irradiation. Studies with strains bearing the leuD21 mutation revealed that inactivation of the supX locus by a nonsense mutation or a deletion results in a complete lack of ability to produce induced Leu+ reversion mutations after UV irradiation. Suppression of the nonsense supX mutation or the presence of an Escherichia coli K-12 F'-borne supX+ allele restored the capacity for induced reversions and increased cell survival after UV irradiation. Introduction of plasmid pKM101 into supX mutant strains also restored their capacity for UV mutagenesis as well as increased survival. The possible nature of the supX gene product and mechanisms by which it may affect expression of the inducible SOS error-prone repair system are considered.
带有supX突变的鼠伤寒沙门氏菌菌株比野生型对紫外线(UV)照射杀伤更敏感。对带有leuD21突变的菌株的研究表明,无义突变或缺失使supX基因座失活会导致在紫外线照射后完全丧失产生诱导型Leu +回复突变的能力。无义supX突变的抑制或大肠杆菌K - 12 F'携带的supX +等位基因的存在恢复了诱导回复的能力,并增加了紫外线照射后的细胞存活率。将质粒pKM101导入supX突变菌株也恢复了它们的紫外线诱变能力以及提高了存活率。文中考虑了supX基因产物的可能性质及其可能影响诱导型SOS易错修复系统表达的机制。