Structures of complexes between echinomycin and duplex DNA
Structures of complexes between echinomycin and duplex DNA
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DOI：
10.1107/s090744490500137x
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发表时间：
2005-04-01
影响因子：
2.2
通讯作者：
Sheldrick, GM
中科院分区：
文献类型：
--
作者：
Cuesta-Seijo, JA;Sheldrick, GM
用较高的分辨率(1.4埃)重新确定了去脂肽抗生素棘球菌素与(CGTACG)(2)的双嵌插络合物的结构，并报道了棘球菌素与(GCGTACGC)(2)和(ACGTACGT)(2)的新的高分辨结构(1.1-1.5埃)。这些结构显示了预期的Hoogsteen配对和Watson-Crick配对，其中预期的Hoogsteen配对用于外部插入发色团的两侧的碱基对，以及Watson-Crick配对用于包绕棘霉素的两个碱基对。在八聚体复合体中，而不是六聚体复合体中，棘球菌素分子表现出两重无序，如果没有硫代缩醛桥，它将具有分子双轴。在所有的结构中，碱基对和生色团的堆积都通过分子间堆积来扩展。这些结构提供了比以前更精确的双嵌插抗生素和双链DNA之间的氢键和其他相互作用的细节。
The structure of the bis-intercalation complex of the depsipeptide antibiotic echinomycin with (CGTACG)(2) has been redetermined at a higher resolution (1.4 angstrom) and new high-resolution structures (1.1-1.5 angstrom) are reported for the complexes of echinomycin with (GCGTACGC)(2) (at both low and high ionic strengths) and (ACGTACGT)(2). The structures show the expected Hoogsteen pairing for the base pairs flanking the intercalating chromophores on the outside and Watson-Crick pairing for both base pairs enclosed by the echinomycin. In the octamer complexes but not the hexamer complex, the echinomycin molecule, which would possess a molecular twofold axis were it not for the thioacetal bridge, shows twofold disorder. In all the structures the stacking of the base pairs and chromophores is extended by intermolecular stacking. The structures provide more precise details of the hydrogen bonding and other interactions between the bis-intercalating antibiotics and the duplex DNA than were previously available.