Table 29.2: Eukaryotic RNA polymerases

Type

Location

Cellular transcripts

Effects of α-amanitin

I

Nucleolus

18S, 5.8S, and 28S rRNA

Insensitive

II

Nucleoplasm

mRNA precursors and snRNA

Strongly inhibited

III

Nucleoplasm

tRNA and 5S rRNA

Inhibited by high concentrations