Bacteria vs. Eukaryote Translation

Question 1

In bacteria, transcription and translation are coupled because:

Answer 1

• there is no nuclear membrane separating the machinery.
• transcription (nucleus) and translation (cytoplasm) are separate processes in eukaryotes

Question 2

In bacteria, there is only one initiation event for the trancription of several genes. This means that bacteria mRNA are:

Answer 2

• polycistronic
  
  • a single mRNA codes for multiple proteins

Question 3

Shine Dalgarno sequence:

Answer 3

• a ribosomal RNA binding site in bacteria mRNA
• generally located around 8 bases upstream of the start codon AUG
• dictates initiation

Question 4

Bacterial ribosomes are smaller and sufficiently divergent from mammalian ribosomes to allow for:

Answer 4

• selective inhibition by the ribosome inhibitor class of antibiotics
  
  • however, ribosome inhibitors typically do have residual toxicity due to their effects on mitochondrial ribosomes, which are more similar to bacterial ribosomes

Question 5

Bacterial ribosome inhibitors typically have residual toxicity due to their effects on mitochondrial ribosomes. This is because:

Answer 5

• mitochondrial ribosomes are similar to bacterial ribosomes

Question 6

Do eIF4E and eIF4G have bacteria counterparts?

Answer 6

• No, because bacterial mRNA does not have a 5’ cap.
  
  • eIF4E and eIF4G bind to the 5’ cap of eukaryotic mRNA