MDCH Drugs

Question 1

Rifamycin (Rifampin)

Answer 1

• Interfere with early stages of Initiation, RNA synthesis.
• Blocks RNA Polymerase by interacting with the beta-subunit
• Used to treat Tuberculosis

Question 2

Myxopyronin and Lipiarmycin

Answer 2

• Drugs that target the Switch Region

- Target bacterial RNA Polymerase

Question 3

Actinomycin D (Dactinomycin)

Answer 3

• Inhibits Prokaryotic and Eukaryotic RNA Polymerase
• Binds tightly to double helical DNA preventing it to act as a template
• Inhibits growth of rapidly dividing cells which could bu used to fight some cancers

Question 4

NeoB

Answer 4

• An aminoglycoside

- Potent inhibitor of RNase P

Question 5

Puromycin

Answer 5

• Peptidyl Transferase Center (PTC) Antibiotic

- Resembles 3’ end of Tyr-tRNA causing premature termination

Question 6

Streptomycin

Answer 6

• Peptidyl Transferase Center (PTC) Antibiotic
• Binds to 30s ribosomal subunit preventing initiation complex formation
• An aminoglycoside
• Can also cause misreading of mRNA
• Can result in hearing loss

Question 7

Tetracycline

Answer 7

• Peptidyl Transferase Center (PTC) Antibiotic
• Binds to 30s ribosomal subunit preventing the binding of aminoacyl-tRNA to the A-site
• A Polyketide Antibiotic
• Effects are reversible if drug is removed. Some resistance has been developed due to overuse

Question 8

Chloramphenicol

Answer 8

• Peptidyl Transferase Center (PTC) Antibiotic
• Binds to 50s subunit and prevents the binding of the amino acid portion of the aminoacyl-tRNA; inhibiting Peptidyltransferase activity
• Used only in extreme cases; Meningitis and Typhoid Fever. Enters human mitochondria and inhibits protein synthesis

Question 9

Erythromycin

Answer 9

• Peptidyl Transferase Center (PTC) Antibiotic
• Macrolide Antibiotic
• Binds to 50s subunit preventing the Translocation step from the A to P site
• Often used in patients that are allergic to penicillin. Low side effects
• Clarithromycin is a close relative drug

Question 10

Lincosamides (Lincomycin)

Answer 10

• Interacts with both the A and P sites on the 50s subunit hampering tRNA positioning and peptide bond formation

Question 11

Cycloheximide

Answer 11

• Inhibits Peptidyl Transferase on the Eukaryotic large subunit

Question 12

Fusidic Acid

Answer 12

• Inhibits elongation in bacteria by binding to EF-G*GDP to prevent dissociation from the large subunit

Question 13

Ricin/ Abrin

Answer 13

• Protein made by the Castor Oil plant

- Catalytically inactivates the Eukaryotic large subunit