Question

What transcripts will be most affected by low levels of α-amanitin? a. 18S and 28S rRNAs b. pre-mRNAs c. 5S rRNAs and tRNAs d. other small nuclear RNAs

Short answer

Option b is correct.

Step-by-step solution

Step 1. Introduction

The α-amanitin is an oligopeptide toxin produced by the mushroom called amanitin. They affect all three RNA polymerases very differently.

Step 2. Explanation of the correct option

Option b is correct because pre-RNA will be most affected if the α-amanitin level decrease as polymerase II is extremely sensitive to α-amanitin.

RNA polymerase I is insensitive to α-amanitin. RNA polymerase II is extremely to α-amanitin and RNA polymerase III is moderately sensitive to α-amanitin.

Step 3. Explanation of the incorrect options

Option a is incorrect because 18S and 28S rRNAs are not affected by α-amanitin as RNA polymerase I is insensitive to α-amanitin.

Option c is incorrect because 5S rRNAs and tRNAs are not affected by α-amanitin as RNA polymerase III is moderately sensitive to α-amanitin.

Option d is incorrect because 5S rRNAs, tRNAs and small nuclear RNA are not affected by α-amanitin as RNA polymerase III is moderately sensitive to α-amanitin