Roles of pIII in filamentous phage assembly
Roles of pIII in filamentous phage assembly
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DOI：
10.1006/jmbi.1998.2006
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发表时间：
1998-09-11
影响因子：
5.6
通讯作者：
Model, P
中科院分区：
文献类型：
--
作者：
Rakonjac, J;Model, P
细丝状噬菌体蛋白LII(PIII)位于噬菌体的一端，是颗粒的感染性和稳定性所必需的。感染了Lit基因已被完全删除的噬菌体的细胞产生的颗粒不会释放到培养基中，但会留在表面。这些颗粒比正常噬菌体要长得多。它们可以通过随后表达PIII来释放。在电子显微镜下，感染基因III缺失噬菌体的细胞被装饰着类似于极长药丸的结构。令人惊讶的是，这样的细胞是活的，可以形成克隆。药物缺乏可以在反式中补充，但存在一个阈值浓度，低于这个浓度就不会发生组装。超过这个阈值，PIII被非常有效地利用，并被并入有感染性但比单位长度更长的噬菌体中。随着PIII浓度的增加，感染颗粒的数量增加，其平均长度减少。PIII稳定PVI，这是在颗粒PIII末端发现的第二种噬菌体蛋白。在没有PIII的情况下，PVI的降解非常迅速。因此，PIII不仅是感染性和颗粒稳定性所必需的，而且是终止组装并将噬菌体从其组装部位释放出来所必需的。(C)1998年学术出版社。
Filamentous phage protein LII (pIII), located at one end of the phage, is required for infectivity and stability of the particle. Cells infected with phage from which gene LIT has been completely deleted produce particles that are not released into the medium but stay associated at the surface. These particles are much longer than normal phage. They can be released by subsequent expression of pIII. Viewed with the electron microscope, cells infected with gene III deletion phage are decorated with structures that resemble extremely long pill. Surprisingly, such cells are viable and can form colonies.The pill deficiency can be complemented in trans, but there is a threshold concentration below which assembly does not occur. Above this threshold, pIII is used very efficiently and is incorporated into infectious but longer than unit length phage. As the concentration of pIII is increased, the number of infectious particles increases, and their average length decreases.pIII stabilizes pVI, a second phage protein found at the pIII end of the particle. Ln the absence of pIII, degradation of pVI is very rapid.pIII is thus not only required for infectivity and particle stability, but to terminate assembly and release the phage from its assembly site. (C) 1998 Academic Press.