6.2 RNA polymerase

What are each component (think of like building blocks) for a prokaryotic RNA polymerase?

RNA polymerase holoenzyme / sigma / 2 alpha / 2 beta / omega

State of function of the sigma part of a prokaryotic RNA polymerase

Promotor recognition

State of function of the alpha part of a prokaryotic RNA polymerase

Assembly / activation

State of function of the beta part of a prokaryotic RNA polymerase

Catalysis / termination 

State of function of the omega part of a prokaryotic RNA polymerase

Assembly, folding / required for some genes

What do the alpha subunits in prokaryotic RNA polymerase activate?

The RNA polymerase

When the prokaryotic RNA moves off the promoter to start transcribing, what does it lose?

The sigma subunit

When is the sigma subunit lost?

When the RNA moves off the promoter to start transcribing

After the sigma subunit is released, what happens to the core enzyme?

Core enzyme aabb is competent for elongation

What is the ‘core enzyme’ composed of?

All enzymes except sigma

How many eukaryotic RNA polymerases?

3

Which subunit is responsible for stopping transcription in prokaryotes?

Beta

Which RNA polymerase is the most abundant one in eukaryotes?

Pol I

What is Pol I for?

Ribosomal RNA genes (rRNA)

What is Pol II for?

Protein coding genes (mRNA) / small nuclear RNA (snRNA)

What is Pol III for?

Transfer RNA (tRNA) / rRNA / snRNA