Localized denaturation of oriT DNA within relaxosomes of the broad-host-range plasmid R1162.
Localized denaturation of oriT DNA within relaxosomes of the broad-host-range plasmid R1162.
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广泛宿主范围质粒 R1162 的松弛体中 oriT DNA 的局部变性。
DOI：
10.1111/j.1365-2958.1995.mmi_17040727.x
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发表时间：
1995
影响因子：
3.6
通讯作者：
Meyer,RJ
中科院分区：
文献类型：
--
作者：
Zhang,S;Meyer,RJ
广泛宿主范围的多拷贝质粒R1162在接合过程中被自传递质粒R751有效动员。松弛体是质粒DNA和R1162编码蛋白的复合物，在转移起点（oriT）形成，是动员所必需的。转移是通过该结构内DNA的链特异性和位点特异性切口启动的。我们表明，通过探测与高锰酸钾thatoriTDNA是局部融化的松弛体内，在该地区从反向重复的网站是有缺口的。在iT的这个区域中的突变，以及在编码松弛体的蛋白质组分的基因中的突变，影响DNA的切口和熔化。松弛体中的切口蛋白是MobA，其也在一轮转移的终止处连接转移的线性单链。我们提出，这两种MobA依赖性DNA加工反应的底物存在潜在的相似性。我们还表明，MobA在转移中具有额外的作用，超越了iTDNA的切口和重新密封。
The broad‐host‐range, multicopy plasmid R1162 is efficiently mobilized during conjugation by the self‐transmissible plasmid R751. The relaxosome, a complex of plasmid DNA and R1162‐encoded proteins, forms at the origin of transfer (oriT) and is required for mobilization. Transfer is initiated by strand‐ and site‐specific nicking of the DNA within this structure. We show by probing with potassium permanganate thatoriTDNA is locally melted within the relaxosome, in the region from the inverted repeat to the site that is nicked. Mutations in this region oforiT, and in genes encoding the protein components of the relaxosome, affect both nicking and melting of the DNA. The nicking protein in the relaxosome is MobA, which also ligates the transferred linear, single strand at the termination of a round of transfer. We propose that there is an underlying similarity in the substrates for these two MobA‐dependent, DNA‐processing reactions. We also show that MobA has an additional role in transfer, beyond the nicking and resealing oforiTDNA.