Temperature‐dependent expression of conjugation pili by IncM plasmid‐harbouring bacteria: Identification of plasmid‐encoded regulatory functions
Temperature‐dependent expression of conjugation pili by IncM plasmid‐harbouring bacteria: Identification of plasmid‐encoded regulatory functions
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IncM 质粒携带细菌对接合菌毛的温度依赖性表达：质粒编码调节功能的鉴定
DOI：
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发表时间：
1994
影响因子：
3.1
通讯作者：
H. Tschäpe
中科院分区：
文献类型：
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作者：
E. Tietze;H. Tschäpe
IncM质粒R446的1.3 kb DNA片段，如果克隆到多拷贝质粒中，则可反式抑制携带IncM质粒的宿主细菌的接合皮利表达，如其对IncM菌毛依赖性噬菌体CIMM不敏感所示（Iml，对CIMM介导的裂解不敏感）。该DNA片段的核苷酸序列的测定、缺失的引入和转座子插入的分析揭示了负责Iml表型的两个决定因素，imlA和imlB。含有imlA的80 bp的DNA片段和含有imlB的约450 bp的相邻DNA片段一起在30 °C下抑制接合皮利的典型表达。转座启动子探针的引入和相应lacZ融合体的构建表明在包含imlA和imlB的区域中重叠的互补链的体内转录。此外，报告基因的表达揭示了imlA-imlB-区域在一个方向上的温度依赖性转录。
A 1,3 kb DNA fragment of the IncM plasmid R446, if cloned in a multicopy plasmid, inhibits in trans the expression of conjugation pili by IncM plasmid‐harbouring host bacteria as indicated by their insensitivity to the IncM pilus‐dependent bacteriophage ϕM (Iml, insensitivity to ϕM‐mediated lysis). Determination of the nucleotide sequence of this DNA fragment, the introduction of deletions and the analysis of transposon insertions reveal two determinants, imlA and imlB, responsible for the Iml phenotype. A stretch of 80 bp of DNA containing imlA and about 450 bp of adjacent DNA comprising imlB, together, bring about inhibition of the typical expression of conjugation pili at 30 °C. The introduction of a transposable promoter probe and the construction of respective lacZ fusions indicate transcription of complementary strands in vivo overlapping in the region comprising imlA and imlB. Moreover, the expression of reporter genes discloses temperature‐dependent transcription of the imlA‐imlB‐region in one direction.