Siegel E C
J Bacteriol. 1973 Jan;113(1):145-60. doi: 10.1128/jb.113.1.145-160.1973.
An ultraviolet (UV)-sensitive mutator gene, mutU, was identified in Escherichia coli K-12. The mutation mutU4 is very close to uvrD, between metE and ilv, on the E. coli chromosome. It was recessive as a mutator and as a UV-sensitive mutation. The frequency of reversion of trpA46 on an F episome was increased by mutU4 on the chromosome. The mutator gene did not increase mutation frequencies in virulent phages or in lytically grown phage lambda. The mutU4 mutation predominantly induced transitional base changes. Mutator strains were normal for recombination and host-cell reactivation of UV-irradiated phage T1. They were normally resistant to methyl methanesulfonate and were slightly more sensitive to gamma irradiation than Mut(+) strains. UV irradiation induced mutations in a mutU4 strain, and phage lambda was UV-inducible. Double mutants containing mutU4 and recA, B, or C were extremely sensitive to UV irradiation; a mutU4 uvrA6 double mutant was only slightly more sensitive than a uvrA6 strain. The mutU4 uvrA6 and mutU4 recA, B, or C double mutants had mutation rates similar to that of a mutU4 strain. Two UV-sensitive mutators, mut-9 and mut-10, isolated by Liberfarb and Bryson in E. coli B/UV, were found to be co-transducible with ilv in the same general region as mutU4.
在大肠杆菌K-12中鉴定出一个对紫外线（UV）敏感的诱变基因mutU。突变体mutU4在大肠杆菌染色体上非常靠近uvrD，位于metE和ilv之间。作为诱变基因和对UV敏感的突变，它是隐性的。染色体上的mutU4增加了F附加体上trpA46的回复频率。该诱变基因不会增加烈性噬菌体或溶菌生长的噬菌体λ中的突变频率。mutU4突变主要诱导转换碱基变化。诱变菌株在紫外线照射的噬菌体T1的重组和宿主细胞再激活方面是正常的。它们对甲磺酸甲酯具有正常抗性，并且比Mut(+)菌株对γ射线照射稍微更敏感。紫外线照射在mutU4菌株中诱导突变，并且噬菌体λ是紫外线可诱导的。含有mutU4和recA、B或C的双突变体对紫外线照射极其敏感；mutU4 uvrA6双突变体仅比uvrA6菌株稍微更敏感一点。mutU4 uvrA6和mutU4 recA、B或C双突变体的突变率与mutU4菌株相似。Liberfarb和Bryson在大肠杆菌B/UV中分离出的两个对紫外线敏感的诱变基因mut-9和mut-10，被发现与ilv共转导，位于与mutU4相同的大致区域。
