Henderson S T, Petes T D
Department of Biology, University of North Carolina, Chapel Hill 27599-3280.
Genetics. 1993 May;134(1):57-62. doi: 10.1093/genetics/134.1.57.
Inverted repeated DNA sequences are common in both prokaryotes and eukaryotes. We found that a plasmid-borne 94 base-pair inverted repeat (a perfect palindrome of 47 bp) containing a poly GT sequence is unstable in S. cerevisiae, with a minimal deletion frequency of about 10(-4)/mitotic division. Ten independent deletions had identical end points. Sequence analysis indicated that all deletions were the result of a DNA polymerase slippage event (or a recombination event) involving a 5-bp repeat (5' CGACG 3') that flanked the inverted repeat. The deletion rate and the types of deletions were unaffected by the rad52 mutation. Strains with the pms1 mutation had a 10-fold elevated frequency of instability of the inverted repeat. The types of sequence alterations observed in the pms1 background, however, were different than those seen in either the wild-type or rad52 genetic backgrounds.
反向重复DNA序列在原核生物和真核生物中都很常见。我们发现，一个携带质粒的94个碱基对的反向重复序列（一个47 bp的完美回文序列），包含一个多聚GT序列，在酿酒酵母中不稳定，最小缺失频率约为10^(-4)/有丝分裂。十个独立的缺失具有相同的终点。序列分析表明，所有缺失都是涉及反向重复序列两侧一个5 bp重复序列（5' CGACG 3'）的DNA聚合酶滑动事件（或重组事件）的结果。缺失率和缺失类型不受rad52突变的影响。具有pms1突变的菌株反向重复序列的不稳定频率提高了10倍。然而，在pms1背景中观察到的序列改变类型与野生型或rad52遗传背景中看到的不同。
