Ivanchenko O B, Il'inskaia O N, Karamova N S, Kipenskaia L V, Leshchinskaia I B
Mikrobiologiia. 1997 Jul-Aug;66(4):444-8.
This paper deals with the induction of the SOS-functions of a bacterial cell by the exogenous ribonuclease of Bacillus intermedius. Two test systems were employed, which made it possible to quantitatively estimate SOS-response induction activity in gram-positive and gram-negative bacteria. It was established that the catalytically active enzyme elicits the SOS-response in the cells of Escherichia coli PQ 37 and causes prophage induction in the lysogenic strain Bacillus subtilis 168 phi 105 WT (a phenomenon related to the SOS-response). An enzyme with a His101Glu-substituted active center, exhibiting residual catalytic activity, failed to induce the SOS-response in an SOS-chromotest with E. coli PQ 37, indicating dependence of the SOS-inducing effect of the enzyme on its catalytic activity. It is suggested that the effect of active ribonuclease on membrane-bound and cytoplasmic RNA causes a change in the nucleotide pool and, as a consequence, elicits the SOS-response of the cell.
本文探讨了中间芽孢杆菌的外源性核糖核酸酶对细菌细胞SOS功能的诱导作用。采用了两种测试系统，这使得定量评估革兰氏阳性菌和革兰氏阴性菌中SOS应答诱导活性成为可能。已证实，具有催化活性的该酶可在大肠杆菌PQ 37细胞中引发SOS应答，并在溶原性菌株枯草芽孢杆菌168 phi 105 WT中引起原噬菌体诱导（这一现象与SOS应答相关）。在活性中心被His101Glu取代、表现出残余催化活性的一种酶，在对大肠杆菌PQ 37进行的SOS显色测试中未能诱导SOS应答，这表明该酶的SOS诱导效应依赖于其催化活性。有人提出，活性核糖核酸酶对膜结合RNA和细胞质RNA的作用会导致核苷酸库发生变化，进而引发细胞的SOS应答。
