Rattray A, Altuvia S, Mahajna G, Oppenheim A B, Gottesman M
J Bacteriol. 1984 Jul;159(1):238-42. doi: 10.1128/jb.159.1.238-242.1984.
We have studied the regulation of the lambda cII gene in vivo using cloned lambda fragments. Lambda N protein stimulated cII expression. Surprisingly, although very high cII protein levels were detected by gel electrophoresis, little cII protein activity, measured as stimulation of the lambda pI and pE promoters, was observed. The half-life of cII protein depended critically on its initial level. At low concentrations its half-life was as short as 1.5 min, whereas at high cII protein levels, it could be as long as 22 min. The Escherichia coli mutant ER437 directs lambda towards lysogeny; cII protein was more stable in this strain than in the wild type. On the other hand, although cyclic AMP is required for efficient lysogeny, it did not appear to influence the synthesis, stability, or activity of cII protein.
我们利用克隆的λ片段在体内研究了λ cII基因的调控。λ N蛋白刺激cII表达。令人惊讶的是，尽管通过凝胶电泳检测到非常高的cII蛋白水平，但作为λ pI和pE启动子刺激的指标，几乎没有观察到cII蛋白活性。cII蛋白的半衰期关键取决于其初始水平。在低浓度时，其半衰期短至1.5分钟，而在高cII蛋白水平时，其半衰期可长达22分钟。大肠杆菌突变体ER437使λ趋向溶原状态；cII蛋白在该菌株中比在野生型中更稳定。另一方面，尽管高效溶原需要环腺苷酸，但它似乎不影响cII蛋白的合成、稳定性或活性。
