R391:: a conjugative integrating mosaic comprised of phage, plasmid, and transposon elements
R391:: a conjugative integrating mosaic comprised of phage, plasmid, and transposon elements
复制标题
DOI：
10.1128/jb.184.18.5158-5169.2002
复制
发表时间：
2002-09-01
影响因子：
3.2
通讯作者：
Osborn, AM
中科院分区：
文献类型：
--
作者：
Böltner, D;MacMahon, C;Osborn, AM
接合性染色体整合元件 R391 是 IncJ 类移动遗传元件的原型。 R391 最初在南非普罗维登斯雷氏菌菌株中发现，具有抗生素和汞抗性特征，以及参与诱变 DNA 修复的基因。虽然最初被描述为质粒，但 R391 随后被证明可以整合到细菌染色体中，采用与霍乱弧菌 O139 的 SXT 元件密切相关的噬菌体样整合机制。对 R391 完整 89 kb 核苷酸序列的分析揭示了由源自噬菌体和质粒的元件以及转座元件组成的嵌合结构。共鉴定出96个开放阅读框；其中，30 个无法分配职能。序列相似性表明 R391 的大部分序列与沙门氏菌序列之间存在关系，特别是那些对应于推定接合转移蛋白的序列，这些蛋白与 IncHI1 质粒 R27 相关。鉴定出携带卡那霉素抗性基因的复合转座子和新的插入元件。 R391 上没有鉴定出质粒复制子，这对之前 IncJ 元件是质粒的假设提出了挑战，这表明它们不能自主复制。
The conjugative, chromosomally integrating element R391 is the archetype of the IncJ class of mobile genetic elements. Originally found in a South African Providencia rettgeri strain, R391 carries antibiotic and mercury resistance traits, as well as genes involved in mutagenic DNA repair. While initially described as a plasmid, R391 has subsequently been shown to be integrated into the bacterial chromosome, employing a phage-like integration mechanism closely related to that of the SXT element from Vibrio cholerae O139. Analysis of the complete 89-kb nucleotide sequence of R391 has revealed a mosaic structure consisting of elements originating in bacteriophages and plasmids and of transposable elements. A total of 96 open reading frames were identified; of these, 30 could not be assigned a function. Sequence similarity suggests a relationship of large sections of R391 to sequences from Salmonella, in particular those corresponding to the putative conjugative transfer proteins, which are related to the IncHI1 plasmid R27. A composite transposon carrying the kanamycin resistance gene and a novel insertion element were identified. Challenging the previous assumption that IncJ elements are plasmids, no plasmid replicon was identified on R391, suggesting that they cannot replicate autonomously.