The Vibrio cholerae O1 chromosomal integron
The Vibrio cholerae O1 chromosomal integron
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DOI：
10.1099/00221287-146-10-2605
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发表时间：
2000-10-01
期刊：
影响因子：
--
通讯作者：
Manning, PA
中科院分区：
文献类型：
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作者：
Clark, CA;Purins, L;Manning, PA
在发现霍乱弧菌重复序列 (VCR) 之前，称为整合子 naa 的基因捕获和表达系统通常与抗生素抗性基因盒相关，阵列中的基因通常少于 5 个。描述了一种克隆大型盒阵列末端的方法。 VCR 内保守的限制性位点有助于通过 Southern 杂交进行作图和 VCR 阵列 5' 端的克隆，并且使用适当的片段可以绘制霍乱弧菌染色体区域的物理图谱。对该区域的预测起始点的序列测定揭示了intl4，它是整合酶整合子家族的成员。对来自 El Tor、经典和血清型 O134 霍乱弧菌菌株的这些序列进行比较，确定了 attI 位点的 3' 末端，从而定义了霍乱弧菌染色体之一中的 4 类整合子，并为霍乱弧菌内的类整合子位点特异性重组提供了第一个证据。传导测定证明了 VCR 之间 IntI1 介导的重组。限制性图谱将 intl4 和 26 VCR 基因盒的序列置于霍乱弧菌 O1 菌株 569B 基因组 120 kb 区域内的阵列中。该区域估计包含 150 个 VCR 基因盒，使之前描述的阵列相形见绌。对鳗弧菌、拟态弧菌和许多霍乱弧菌血清型菌株的基因组 DNA 进行 Southern 分析，发现片段与 VCR 特异性探针杂交，但显示出高度的限制性片段长度多态性。这些数据有助于识别拟态拟弧菌的新 5 类整合子的一部分。
Until the discovery of the Vibrio cholerae repeat (VCR), the gene capture and expression systems termed integrons naa been typically associated with antibiotic-resistance gene cassettes with usually less than five genes in an array. A method is described for the cloning of the ends of large cassette arrays. Conserved restriction sites within VCRs facilitated the mapping by Southern hybridization and cloning of the 5' end of the VCR array, and using appropriate fragments it was possible to develop a physical map of the region of the V. cholerae chromosome. Sequence determination of the predicted beginning of this region revealed intl4, a member of the integron family of integrases. Comparison of these sequences from El Tor, Classical and serotype O134 V. cholerae strains identified the 3' end of the attI site, thereby defining the class 4 integron in one of the V. cholerae chromosomes, and providing the first evidence for integron-like site-specific recombination within V. cholerae. Conduction assays demonstrated IntI1-mediated recombination between VCRs. Restriction mapping places the sequences of intl4 and 26 VCR gene cassettes in arrays within a 120 kb region of the V. cholerae O1 strain 569B genome. This region contains an estimated 150 VCR gene cassettes, dwarfing previously described arrays. Southern analysis of genomic DNA from strains of Vibrio anguillarum, Vibrio mimicus and a number of V. cholerae serotypes revealed fragments that hybridized with VCR-specific probes but showed a high degree of restriction fragment length polymorphism. These data facilitate the identification of part of a new class 5 integron from V. mimicus.