Bläsi U, Lubitz W
J Gen Virol. 1985 Jun;66 ( Pt 6):1209-13. doi: 10.1099/0022-1317-66-6-1209.
The phi X174 gene E product (gpE) causes lysis of Escherichia coli by inducing the host autolytic system. Experiments were carried out to ascertain which part of the 91 amino acid polypeptide carries the functional site for this process. For this purpose fusion genes were created comprising the first 51 codons of gene E and unrelated sequences coding for 102 or 33 amino acids respectively. The chimeric protein of 153 amino acids consisting of the N-terminal part of gpE and a fragment of beta-galactosidase, was neither able to lyse E. coli nor to restore beta-galactosidase activity by alpha-complementation. Expression of the 84 amino acid polypeptide, however, was able to induce lysis of E. coli. It is therefore concluded that the functional lysis-inducing site of gpE is located within the cloned N-terminal part of gene E. In the shorter chimeric protein the sequence following the functional site was tolerated or necessary for stabilization, but in the longer chimeric protein, the C-terminal sequence disturbed the lysis-inducing conformation.
噬菌体φX174基因E产物（gpE）通过诱导宿主自溶系统导致大肠杆菌裂解。开展了实验以确定91个氨基酸的多肽的哪一部分携带此过程的功能位点。为此，构建了融合基因，其包含基因E的前51个密码子以及分别编码102个或33个氨基酸的无关序列。由gpE的N端部分和β-半乳糖苷酶片段组成的153个氨基酸的嵌合蛋白，既不能裂解大肠杆菌，也不能通过α-互补恢复β-半乳糖苷酶活性。然而，84个氨基酸多肽的表达能够诱导大肠杆菌裂解。因此得出结论，gpE的功能性裂解诱导位点位于基因E克隆的N端部分内。在较短的嵌合蛋白中，功能位点之后的序列对于稳定化是可耐受的或必需的，但在较长的嵌合蛋白中，C端序列扰乱了裂解诱导构象。
