Expression of leading region genes on Incl1 plasmid Collb-P9: genetic evidence for single-stranded DNA transcription
Expression of leading region genes on Incl1 plasmid Collb-P9: genetic evidence for single-stranded DNA transcription
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DOI：
10.1099/00221287-145-10-2655
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发表时间：
1999-10-01
期刊：
影响因子：
2.8
通讯作者：
Wilkins, BM
中科院分区：
文献类型：
--
作者：
Bates, S;Roscoe, RA;Wilkins, BM
在细菌结合中，质粒的前导区是第一个进入受体细胞的部分。Incl1质粒ColIb-P9的这一部分包括在接合感染细胞早期在瞬时脉冲中转录的基因，以促进迁移质粒的建立。有证据表明，基因表达的爆发是由一个过程调节的，该过程独立于抑制子，但依赖于基因在接合转移的独特质粒链上的方向。测定了前导区11.7kb的核苷酸序列，发现含有10个ORF；所有的定位都使得用于转录的模板链与转移的链相对应。前导区包含三个分散的重复序列，该序列与H.Masai和K.Arai(1997，Cell 89,897-907)描述的ssDNA中的一个新启动子同源。有人认为，重复序列是在ColIb转移链中形成的启动子，以支持在接合早期转移的基因的瞬时转录。
The leading region of a plasmid is the first sector to enter the recipient cell in bacterial conjugation. This sector of Incl1 plasmid ColIb-P9 includes genes that are transcribed in a transient pulse early in the conjugatively infected cell to promote establishment of the immigrant plasmid. Evidence is presented that the burst of gene expression is regulated by a process which is independent of a repressor but dependent on the orientation of the genes on the unique plasmid strand transferred in conjugation. The nucleotide sequence of 11.7 kb of the leading region was determined and found to contain 10 ORFs; all are orientated such that the template strand for transcription corresponds to the transferred strand. The leading region contains three dispersed repeats of a sequence homologous to a novel promoter in ssDNA described by H. Masai & K. Arai (1997, Cell 89, 897-907). It is proposed that the repeats are promoters that form in the transferring strand of ColIb to support transient transcription of genes transferred early in conjugation.