Transport of Phage P22 DNA across the Cytoplasmic Membrane
Transport of Phage P22 DNA across the Cytoplasmic Membrane
复制标题
噬菌体 P22 DNA 跨细胞质膜的运输
作者：
G. L. Perez;Bao;M. Slater;S. Maloy
摘要尽管人们对噬菌体P22的生命周期了解很多，但对噬菌体DNA转运到沙门氏菌中的机制却知之甚少。P22 DNA最初被喷射到周质空间中，随后被转运到宿主细胞质中。三种噬菌体编码的蛋白质（gp16、gp20和gp7）与DNA共喷射。为了检验这些蛋白质中的一种或多种介导DNA跨细胞质膜转运的假设，我们纯化了gp16、gp20和gp7，并分析了它们与细胞膜结合以及促进DNA在体外被膜囊泡吸收的能力。膜缔合实验表明，gp16分配到膜部分，而gp20和gp7留在可溶性部分。此外，加入gp16，而不是gp7或gp20，脂质体预载荧光染料促进染料的释放。32P标记的DNA进入脂质体的运输仅发生在gp16和人工产生的膜电位的存在下。两者合计，这些结果表明，gp16分区到细胞质膜和介导的P22 DNA跨沙门氏菌的细胞质膜的主动运输。
ABSTRACT Although a great deal is known about the life cycle of bacteriophage P22, the mechanism of phage DNA transport into Salmonella is poorly understood. P22 DNA is initially ejected into the periplasmic space and subsequently transported into the host cytoplasm. Three phage-encoded proteins (gp16, gp20, and gp7) are coejected with the DNA. To test the hypothesis that one or more of these proteins mediate transport of the DNA across the cytoplasmic membrane, we purified gp16, gp20, and gp7 and analyzed their ability to associate with membranes and to facilitate DNA uptake into membrane vesicles in vitro. Membrane association experiments revealed that gp16 partitioned into the membrane fraction, while gp20 and gp7 remained in the soluble fraction. Moreover, the addition of gp16, but not gp7 or gp20, to liposomes preloaded with a fluorescent dye promoted release of the dye. Transport of 32P-labeled DNA into liposomes occurred only in the presence of gp16 and an artificially created membrane potential. Taken together, these results suggest that gp16 partitions into the cytoplasmic membrane and mediates the active transport of P22 DNA across the cytoplasmic membrane of Salmonella.
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影响因子：
3.7
作者：
Kemp, P;Garcia, LR;Molineux, IJ
通讯作者：
Molineux, IJ
DOI：
10.1073/pnas.90.9.4295
发表时间：
1993-05-01
影响因子：
11.1
作者：
DESPICER, PO;MALOY, S
通讯作者：
MALOY, S
沙门氏菌噬菌体 P22 突变体存在转导失败的缺陷。
影响因子：
3.3
作者：
Benson,NR;Roth,J
通讯作者：
Roth,J
引导蛋白参与 P22 衣壳组装的启动。
影响因子：
3.7
作者：
Thomas,D;PreveligeJr,P
通讯作者：
PreveligeJr,P