Diversification of host range within the IncP-1 plasmid group
Diversification of host range within the IncP-1 plasmid group
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IncP-1 质粒组内宿主范围的多样化
DOI：
10.1099/mic.0.068387-0
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发表时间：
2013
期刊：
影响因子：
1.5
通讯作者：
and Top E.M.
中科院分区：
文献类型：
--
作者：
Yano;H.;Rogers;L.M.;Molly K.;Heuer;H.;Smalla;K.;Brown C.J.;and Top E.M.
广宿主范围质粒在抗生素耐药性和其他性状的传播中起着关键作用。尽管有关密切相关质粒的基因组多样性的信息越来越多，但序列差异和宿主范围之间的关系仍然不清楚。IncP-1质粒目前根据骨架基因的遗传距离分为六个亚组。我们使用两个IncP-1γ质粒、一个IncP-1β质粒及其微复制子研究了来自两个亚组的质粒是否表现出不同的宿主范围。比较了α-变形菌、β-变形菌和γ-变形菌中5种菌对质粒构建和维持的影响。在没有选择的情况下，IncP-1β质粒在所有五种宿主中复制并持续存在。两个IncP-1γ质粒均不能在α变形菌宿主日本鞘氨醇杆菌中复制，一个在根癌农杆菌中建立，但非常不稳定。相比之下，两种IncP-1γ微复制子（其产生比野生型质粒更高水平的复制起始蛋白）在所有菌株中复制，表明天然质粒的不良建立部分是由于次优的复制起始基因调控。研究结果表明，不同IncP-1质粒的宿主范围仅部分重叠，这可能限制质粒重组，从而导致进一步的基因组分化。
Broad-host-range plasmids play a critical role in the spread of antibiotic resistance and other traits. In spite of increasing information about the genomic diversity of closely related plasmids, the relationship between sequence divergence and host range remains unclear. IncP-1 plasmids are currently classified into six subgroups based on the genetic distance of backbone genes. We investigated whether plasmids from two subgroups exhibit a different host range, using two IncP-1γ plasmids, an IncP-1β plasmid and their minireplicons. Efficiencies of plasmid establishment and maintenance were compared using five species that belong to theAlphaproteobacteria,BetaproteobacteriaandGammaproteobacteria. The IncP-1β plasmid replicated and persisted in all five hosts in the absence of selection. Of the two IncP-1γ plasmids, both were unable to replicate in alphaproteobacterial hostSphingobium japonicum, and one established itself inAgrobacterium tumefaciensbut was very unstable. In contrast, both IncP-1γ minireplicons, which produced higher levels of replication initiation protein than the wild-type plasmids, replicated in all strains, suggesting that poor establishment of the native plasmids is in part due to suboptimal replication initiation gene regulation. The findings suggest that host ranges of distinct IncP-1 plasmids only partially overlap, which may limit plasmid recombination and thus result in further genome divergence.