The complete DNA sequence and analysis of R27, a large IncHI plasmid from Salmonella typhi that is temperature sensitive for transfer
The complete DNA sequence and analysis of R27, a large IncHI plasmid from Salmonella typhi that is temperature sensitive for transfer
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DOI：
10.1093/nar/28.10.2177
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发表时间：
2000-05-15
影响因子：
14.9
通讯作者：
Taylor, DE
中科院分区：
文献类型：
--
作者：
Sherburne, CK;Lawley, TD;Taylor, DE
伤寒沙门氏菌是伤寒的病原体，全世界每年有1600万人感染，60万人死亡。伤寒沙门氏菌多重耐药的质粒编码通常是由H （IncH）不相容基团的质粒编码。对IncHI1家族的原型质粒R27的完整DNA序列进行了编译和分析，该180kb的质粒包含210个开放阅读框（orf），其中14个已被鉴定，56个与其他质粒和原核生物的orf相似。许多插入元件被发现，包括完整的Tn10转座子，它携带四环素抗性基因。存在两个转移区，Tra1和Tra2，它们之间至少相隔64 kb。在其他系统中作为温度调节抑制因子的dna结合蛋白TIpA和H-NS的同源物已经定位在R27中，转移和复制区域的序列分析支持R27的马赛克样结构。已经确定了负责偶联和质粒维持的基因，并讨论了负责热敏转移的机制。
Salmonella typhi, the causative agent of typhoid fever, annually infects 16 million people and kills 600 000 world wide. Plasmid-encoded multiple drug resistance in S. typhi is always encoded by plasmids of incompatibility group H (IncH). The complete DNA sequence of the large temperature-sensitive conjugative plasmid R27, the prototype for the IncHI1 family of plasmids, has been compiled and analyzed, This 180 kb plasmid contains 210 open reading frames (ORFs), of which 14 have been previously identified and 56 exhibit similarity to other plasmid and prokaryotic ORFs. A number of insertion elements were found, including the full Tn10 transposon, which carries tetracycline resistance genes. Two transfer regions, Tra1 and Tra2, are present, which are separated by a minimum of 64 kb. Homologs of the DNA-binding proteins TIpA and H-NS that act as temperature-regulated repressors in other systems have been located in R27, Sequence analysis of transfer and replication regions supports a mosaic-like structure for R27. The genes responsible for conjugation and plasmid maintenance have been identified and mechanisms responsible for thermosensitive transfer are discussed.