Poteete A R, Fenton A C
Department of Molecular Genetics & Microbiology, University of Massachusetts Medical School, Worcester, Massachusetts 01655, USA.
J Bacteriol. 2000 Apr;182(8):2336-40. doi: 10.1128/JB.182.8.2336-2340.2000.
Recombination between short linear double-stranded DNA molecules and Escherichia coli chromosomes bearing the red genes of bacteriophage lambda in place of recBCD was tested in strains bearing mutations in genes known to affect recombination in other cellular pathways. The linear DNA was a 4-kb fragment containing the cat gene, with flanking lac sequences, released from an infecting phage chromosome by restriction enzyme cleavage in the cell; formation of Lac(-) chloramphenicol-resistant bacterial progeny was measured. Recombinant formation was found to be reduced in ruvAB and recQ strains. In this genetic background, mutations in recF, recO, and recR had large effects on both cell viability and on recombination. In these cases, deletion of the sulA gene improved viability and strain stability, without improving recombination ability. Expression of a gene(s) from the nin region of phage lambda partially complemented both the viability and recombination defects of the recF, recO, and recR mutants and the recombination defect of ruvC but not of ruvAB or recQ mutants.
在已知影响其他细胞途径中重组的基因突变菌株中，测试了短线性双链DNA分子与携带噬菌体λ红色基因而非recBCD的大肠杆菌染色体之间的重组。线性DNA是一个包含cat基因的4kb片段，两侧有lac序列，通过细胞内的限制酶切割从感染的噬菌体染色体中释放出来；测量了Lac(-)氯霉素抗性细菌后代的形成。发现ruvAB和recQ菌株中的重组形成减少。在这种遗传背景下，recF、recO和recR中的突变对细胞活力和重组都有很大影响。在这些情况下，sulA基因的缺失提高了活力和菌株稳定性，但没有提高重组能力。来自噬菌体λ nin区域的一个基因的表达部分弥补了recF、recO和recR突变体的活力和重组缺陷以及ruvC的重组缺陷，但不能弥补ruvAB或recQ突变体的缺陷。
