Actinomycin D and α-amanitin are commonly used to inhibit transcription.

α-Amanitin binds to the largest subunits of RNA polymerase II RNAP II and RNAP III, with RNAP II being the most sensitive. As a consequence, the incorporation of new ribonucleotides into the nascent RNA chains is blocked.

Actinomycin D is generally acting thought to intercalate into DNA thereby preventing the progression of RNA polymerases, with RNAP I being the most sensitive.

Thank you! Are these commonly used to inhibit transcription in yeast though? I've read that α-amanatin doesn't inhibit transcription in yeast Article Inhibiting eukaryotic transcription: Which compound to choos...