噬菌体λDNA包装。FI基因的产物促进原头部与DNA末端酶复合物的结合。

Bacteriophage lambda DNA packaging. The product of the FI gene promotes the incorporation of the prohead to the DNA-terminase complex.

作者信息

Becker A, Murialdo H, Lucko H, Morell J

机构信息

Department of Medical Genetics, University of Toronto, Ontario, Canada.

出版信息

J Mol Biol. 1988 Feb 20;199(4):597-607. doi: 10.1016/0022-2836(88)90304-x.

DOI:10.1016/0022-2836(88)90304-x

PMID:2965251

Abstract

Lambda DNA packaging in vitro can be examined in stages. In a first step, lambda DNA interacts with terminase to form a DNA-enzyme complex, called complex I. Upon addition of proheads, in a second step, a ternary complex, complex II, containing DNA, terminase and the prohead is formed. Finally, upon addition of the rest of the morphogenetic components, complete phages are assembled. We have investigated the effect of the FI gene product (gpFI) in these reactions and found that a stimulation in phage yield is observed when gpFI is included early in the reaction, at the time when DNA, terminase and proheads interact to form complex II. Measurements of complex II formation revealed that gpFI stimulated the rate of formation of this intermediate. gpFI was further shown to stimulate the addition of proheads to preformed complexes I to give complex II, but the protein did not stimulate complex I formation.

摘要

体外λ噬菌体DNA包装可分阶段进行检测。第一步，λ噬菌体DNA与末端酶相互作用形成一种DNA - 酶复合物，称为复合物I。第二步，加入原头部后，形成一种三元复合物，即复合物II，它包含DNA、末端酶和原头部。最后，加入其余形态发生成分后，完整的噬菌体得以组装。我们研究了FI基因产物（gpFI）在这些反应中的作用，发现当在反应早期，即DNA、末端酶和原头部相互作用形成复合物II时加入gpFI，噬菌体产量会受到刺激。复合物II形成的测量结果表明，gpFI刺激了这种中间体的形成速率。进一步研究表明，gpFI能刺激将原头部添加到预先形成的复合物I中以形成复合物II，但该蛋白质不刺激复合物I的形成。