Davison A, Leach D R
Institute of Cell and Molecular Biology, University of Edinburgh, UK.
Nucleic Acids Res. 1994 Oct 25;22(21):4361-3. doi: 10.1093/nar/22.21.4361.
In vitro studies have revealed that DNA hairpin-loops usually contain four unpaired bases. However, a small subset of sequences can form two-base loops. We have previously described an in vivo assay that is sensitive to tight loop formation and have set out to test whether DNA sequences known to form two-base loops in vitro also form tight loops in vivo. It is shown that the sequences 5'dCNNG and 5'dTNNA behave as predicted if they favour two-base loop formation in vivo, a result that is consistent with previously described in vitro studies. The ability of specific DNA sequences to form tight loops in vivo has implications for their potential to form transient structures involved in gene regulation, recombination and mutagenesis.
体外研究表明,DNA发夹环通常包含四个未配对碱基。然而,一小部分序列可形成双碱基环。我们之前描述了一种对紧密环形成敏感的体内检测方法,并着手测试已知在体外形成双碱基环的DNA序列在体内是否也形成紧密环。结果表明,如果5'dCNNG和5'dTNNA序列在体内倾向于形成双碱基环,那么它们的表现符合预期,这一结果与之前描述的体外研究一致。特定DNA序列在体内形成紧密环的能力对其形成参与基因调控、重组和诱变的瞬时结构的潜力具有重要意义。