Seong K Y, Chae S K, Kang H S
Department of Microbiology, College of Natural Sciences, Seoul National University, Korea.
Mol Cells. 1997 Apr 30;7(2):284-9.
An E. coli RecA and yeast RAD51 homolog from Aspergillus nidulans, radA, has been cloned by screening genomic and cDNA libraries with a PCR-amplified probe. This probe was generated using primers carrying the conserved sequences of eukaryotic RecA homologs. The deduced amino acid sequence revealed two conserved Walker-A and -B type nucleotide-binding domains and exhibited 88%, 60%, and 53% identity with Mei-3 of Neurospora crassa, rhp51+ of Schizosaccharomyces pombe, and Rad51 of Saccharomyces cerevisiae, respectively. radA null mutants constructed by replacing the whole coding region with a selection marker showed high methyl methanesulfonate (MMS) sensitivity. Heterozygous diploids of radA disruptant with the uvsC114 mutant failed to complement with respect to MMS-sensitivity, indicating that radA is an allele of uvsC. In selecting spontaneous forward selenate resistant mutations, mutator effects were observed in radA null mutants similarly to those shown in uvsC114 mutant strains.
通过用PCR扩增探针筛选构巢曲霉的基因组文库和cDNA文库，克隆出了来自该菌的大肠杆菌RecA和酵母RAD51的同源物radA。该探针是使用携带真核RecA同源物保守序列的引物产生的。推导的氨基酸序列显示出两个保守的沃克A和B型核苷酸结合结构域，分别与粗糙脉孢菌的Mei-3、粟酒裂殖酵母的rhp51+和酿酒酵母的Rad51具有88%、60%和53%的同一性。用选择标记替换整个编码区构建的radA缺失突变体表现出对甲磺酸甲酯（MMS）高度敏感。radA破坏体与uvsC114突变体的杂合二倍体在MMS敏感性方面未能互补，表明radA是uvsC的一个等位基因。在选择自发的对硒酸盐抗性突变时，在radA缺失突变体中观察到了诱变效应，类似于uvsC114突变体菌株中显示的效应。
