Synthesis of low molecular weight RNA components in cells with a temperature-sensitive polymerase II.

AF 8 cells are a mutant cell line of baby hamster kidney cells with a temperature-sensitive polymerase II activity. When these cells grow at the non-permissive temperature (40 degrees C) the syntheseis of low molecular weight RNA components D, C and A is preferentially inhibited, whereas the synthesis of rRNA, tRNA, 5 S RNA and component L is affected only a little or not at all. These results indicate that polymerase II catalyzes the synthesis of components D, C and A.