FIG. 4.

PNPase has different targets from those of RNase R. Cells from which total RNAs were isolated by the hot phenol method are indicated above the respective lanes. The exponentially growing cells were cold shocked at 15°C for 1 h and 5 h, and samples were collected for RNA isolation. Equal amounts of RNA samples were used for primer extension with deoxyoligonucleotide corresponding to the yfiA gene. The products were analyzed by 6% polyacrylamide gel electrophoresis under denaturing conditions.