Tokuno S, Gough M
Mol Gen Genet. 1976 Mar 22;144(2):199-204. doi: 10.1007/BF02428109.
Phage P22 mutation c27 defines a site required for establishment , but not maintenance of repressor synthesis. This study confirms that P22 c27 is able to synthesize repressor if active repressor is present. An interaction involving gene products of c1 and c3 and the site c27 retards expression of the lytic genes of P22. Mutations in gene c1 eliminate the retardation of lytic gene expression, but c27 does not alleviate the retardation. These results are used to construct a model that postulates that binding of c1 and c3 products to DNA at or near c27 is sufficient to cause retardation of lytic gene expression. The functioning of c27 is contrasted to that of the analogous cy mutants of lambda. The effect of the c27 mutation upon alleviation of "cl repression" was studied in a partial revertant of Salmonella typhimurium Pox-1 in which c1 repression is exaggerated. The higher frequency of lysogenization seen in the mutant host is related to enhanced cl repression.
噬菌体P22突变体c27定义了一个建立阻遏物合成所必需的位点，但不是维持该合成所必需的位点。本研究证实，如果存在活性阻遏物，P22 c27能够合成阻遏物。涉及c1和c3基因产物与c27位点的相互作用会延迟P22裂解基因的表达。c1基因中的突变消除了裂解基因表达的延迟，但c27并不能缓解这种延迟。这些结果被用于构建一个模型，该模型假定c1和c3产物在c27或其附近与DNA的结合足以导致裂解基因表达的延迟。将c27的功能与λ噬菌体类似的cy突变体的功能进行了对比。在鼠伤寒沙门氏菌Pox-1的一个部分回复体中研究了c27突变对缓解“cI阻遏”的影响，其中cI阻遏被夸大。在突变宿主中观察到的更高的溶原化频率与增强的cI阻遏有关。
