PHAGE OPERON INVOLVED IN SENSITIVITY TO THE LACTOCOCCUS-LACTIS ABORTIVE INFECTION MECHANISM ABID1
PHAGE OPERON INVOLVED IN SENSITIVITY TO THE LACTOCOCCUS-LACTIS ABORTIVE INFECTION MECHANISM ABID1
复制标题
DOI：
10.1128/jb.177.13.3824-3829.1995
复制
发表时间：
1995-07-01
影响因子：
3.2
通讯作者：
CHOPIN, MC
中科院分区：
文献类型：
--
作者：
BIDNENKO, E;EHRLICH, D;CHOPIN, MC
噬菌体bIL 66不能在含有败育感染基因abiD 1的乳酸乳球菌细胞上生长。使用能够在AbiD 1细胞上生长的自发噬菌体突变体来研究噬菌体-Abi相互作用。一个1.33-kb的突变体噬菌体的DNA片段允许生长的AbiD 1（S）的AbiD 1细胞中，当存在反式。该片段的序列分析揭示了一个操纵子组成的四个开放的阅读框架，指定orf 1至orf 4。操纵子在感染后10分钟从呈现延伸的-10共有序列但没有-35序列的启动子转录。对四个独立的AbiD 1（r）突变体的分析揭示了位于orf 1中的不同点突变，这意味着该开放阅读框架对于AbiD 1的敏感性是必需的。然而，当orf 3在高拷贝数质粒上以反式表达时，敏感性被部分抑制，这表明AbiD 1通过降低可用orf 3产物的浓度来起作用。
Phage bIL66 is unable to grow on Lactococcus lactis cells harboring the abortive infection gene abiD1. Spontaneous phage mutants able to grow on AbiD1 cells were used to study phage-Abi interaction. A 1.33-kb DNA segment of a mutant phage allowed growth of AbiD1(s) phages in AbiD1 cells when present in trans. Sequence analysis of this segment revealed an operon composed of four open reading frames, designated orfl to orf4. The operon is transcribed 10 min after infection from a promoter presenting an extended -10 consensus sequence but no -35 sequence. Analysis of four independent AbiD1(r) mutants revealed a different point mutation localized in orfl, implying that this open reading frame is needed for sensitivity to AbiD1. However, the sensitivity is partly suppressed when orf3 is expressed in trans on a high-copy-number plasmid, suggesting that AbiD1 acts by decreasing the concentration of an available orf3 product.