Genome of Enterobacteriophage Lula/phi80 and insights into its ability to spread in the laboratory environment.
Genome of Enterobacteriophage Lula/phi80 and insights into its ability to spread in the laboratory environment.
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肠杆菌噬菌体 Lula/phi80 的基因组及其在实验室环境中传播能力的见解。
DOI：
10.1128/jb.01353-12
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发表时间：
2012
影响因子：
3.2
通讯作者：
Kuzminov,Andrei
中科院分区：
文献类型：
--
作者：
Rotman,Ella;Kouzminova,Elena;Plunkett3rd,Guy;Kuzminov,Andrei
新的温和噬菌体卢拉，污染实验室大肠杆菌菌株，原来是众所周知的拟杆菌噬菌体phi 80。我们以前的研究表明，Lula/phi 80的两个特征有助于其在实验室环境中的传播：隐蔽的溶原生产力和隐形感染性。为了理解这些特征背后的遗传学/基因组学，我们对Lula/phi 80基因组进行了测序和注释，遇到了一个E.大肠杆菌毒性基因在测序重叠群中显示为缺口，并对少数基因进行了更详细的分析。Lula/phi 80的基因组布局复制了lambda的基因组布局，但与其他类胡萝卜素的同源性主要限于衣壳基因。Lula/phi 80的DNA对几种限制性内切酶的切割具有抗性，这表明DNA发生了修饰，但是缺失噬菌体的sdamL基因（编码DNA腺嘌呤甲基化酶）并不能使DNA发生切割。Lula/phi 80的damL突变也没有改变溶原菌培养物中的噬菌体滴度，而宿主damL突变却使其增加了近100倍。由于Lula/phi 80溶原菌培养物中的高噬菌体滴度显然是对内源性DNA损伤的响应，我们删除了唯一的Lula/phi 80 SOS控制基因dinL。我们发现，inL突变溶原细胞释放较少的噬菌体响应内源性DNA损伤，但在他们的响应外部DNA损伤不变。Lula/phi 80的毒性基因gamL编码宿主ATP依赖性核酸外切酶RecBCD和SbcCD的抑制剂。它自己的解毒剂agt，显然编码一种修饰蛋白，在附近被发现。有趣的是，Lula/phi 80溶原菌是recDandsbcCD表型，因此GamL和Agt是溶原性转化的一部分。
The novel temperate bacteriophage Lula, contaminating laboratory Escherichia coli strains, turned out to be the well-known lambdoid phage phi80. Our previous studies revealed that two characteristics of Lula/phi80 facilitate its spread in the laboratory environment: cryptic lysogen productivity and stealthy infectivity. To understand the genetics/genomics behind these traits, we sequenced and annotated the Lula/phi80 genome, encountering an E. coli-toxic gene revealed as a gap in the sequencing contig and analyzing a few genes in more detail. Lula/phi80's genome layout copies that of lambda, yet homology with other lambdoid phages is mostly limited to the capsid genes. Lula/phi80's DNA is resistant to cutting with several restriction enzymes, suggesting DNA modification, but deletion of the phage'sdamLgene, coding for DNA adenine methylase, did not make DNA cuttable. ThedamLmutation of Lula/phi80 also did not change the phage titer in lysogen cultures, whereas the hostdammutation did increase it almost 100-fold. Since the high phage titer in cultures of Lula/phi80 lysogens is apparently in response to endogenous DNA damage, we deleted the only Lula/phi80 SOS-controlled gene,dinL. We found thatdinLmutant lysogens release fewer phage in response to endogenous DNA damage but are unchanged in their response to external DNA damage. The toxic gene of Lula/phi80,gamL, encodes an inhibitor of the host ATP-dependent exonucleases, RecBCD and SbcCD. Its own antidote,agt, apparently encoding a modifier protein, was found nearby. Interestingly, Lula/phi80 lysogens arerecDandsbcCDphenocopies, so GamL and Agt are part of lysogenic conversion.