The postmaturational cleavage of 23 S ribosomal RNA in Anacystis nidulans is inhibited by infection with cyanophage AS-1.

The 23S (1.1 X 10(6) mol.wt.) rRNA of Anacystis nidulans undergoes postmaturational cleavage to produce 0.9 X 10(6) and 0.2 X 10(6) molecular species. We have provided evidence in double labelling experiments, in which we could distinguish between the fate of molecules synthesized before and after infection, respectively, that infection with cyanophage AS-1 abruptly and completely inhibits the cleavage of 23S rRNA in Anacystis cells.