Chattoraj D K, Younghusband H B, Inman R B
Biophysics Laboratory and Biochemistry Department, University of Wisconsin, Madison, Wisconsin 53706, USA.
Mol Gen Genet. 1975;136(2):139-49. doi: 10.1007/BF00272035.
Three new deletion mutants and an insertion mutant of E. coli bacteriophage P2, del2, vir79, del4 and sig5, were mapped by the electron microscope heteroduplex method. The deletions were found to cover 45.5-51.6%, 75.6-76.7% and 92.3-99.3% respectively of P2 DNA while sig5 represented a 3.7% insertion at 78.6% from the left end. The region covering 75.9-76.7% of P2 DNA is also deleted in the two previously characterized immunity insensitive variants of P2, vir22 and Hy dis. This region may identify the portion of the genome responsible for immunity. The physical and genetic maps of P2 were previously found to be colinear with respect to the two mutations vir22 and vir37. This relationship is confirmed by the position of del2.
通过电子显微镜异源双链法对大肠杆菌噬菌体P2的三个新缺失突变体和一个插入突变体del2、vir79、del4和sig5进行了定位。发现这些缺失分别覆盖P2 DNA的45.5 - 51.6%、75.6 - 76.7%和92.3 - 99.3%，而sig5代表在距左端78.6%处有3.7%的插入。在P2先前鉴定的两个免疫不敏感变体vir22和Hy dis中，也缺失了覆盖P2 DNA 75.9 - 76.7%的区域。该区域可能确定了基因组中负责免疫的部分。先前发现P2的物理图谱和遗传图谱在vir22和vir37这两个突变方面是共线的。del2的位置证实了这种关系。
