Translation #2

Question 1

Name the molecule that binds aminoacyl-tRNA and GTP.

Answer 1

BACTERIA = EF-Tu
EUKARYOTES = eEF-1A

Question 2

Name the molecule that exchanged GTP for GDP.

Answer 2

BACTERIA = EF-TS
EUKARYOTES = eEF-1B

Question 3

Name the molecule that is involved in ribosome translocation.

Answer 3

BACTERIA = EF-G
EUKARYOTES = eEF-2

Question 4

Protein synthesis inhibitors can acts as…

Answer 4

antibiotics

Question 5

Fusidic Acid

Answer 5

~ narrow spectrum steroid antibiotic (MRSA)

~ inhibited elongation at the EF-G step –> binds to EF-G-GDP and prevents its release from ribosome = block A site

Question 6

Puromycin

Answer 6

mimics aminoacyl-tRNA and is added to the peptide chain, the molecule is not anchored to the A site so it falls off

Question 7

Diphtheria toxin

Answer 7

catalyses ADP-ribosylation of eEF-2

~ blocks eukaryotic protein synthesis

Question 8

Ricin

Answer 8

~ type 2 ribosome inactivating protein (RIP)
~ made up of two polypeptide chains (A + B)
Chain B binds galactose which allows it to enter the cell
Chain A binds and hydrolyses rRNA in ribosomes

Question 9

Unique prokaryotic translation facts

Answer 9

~ polycistronic mRNA
~ transcription and translation can occur at the same time
~ definite consensus sentence

Question 10

Unique Eukaryotic translation facts

Answer 10

~ methionine is the 1st a.a. + special form of initiator tRNA
~ some evidence of consensus sequence (Kozak motif)
~ not all the mRNA acts as a template (5’, 3’ untranslated regions)
~ initiation factors (IF, 12 types)