Antibiotics and Mode of Action

Antibiotics are  substances made in nature by various microorganisms that inhibit or kill other microorganisms.

SI.No	Antibiotic	Group	Mode of action
1	Actinomycin D	Prokaryotes	An intercalating agent, binds to DNA especially in the GC region, thus inhibits RNA synthesis. At high concentration, it blocks DNA replication.
2	Anthrocyclins	Prokaryotes	Inhibits DNA replication and transcription.
3	Chloramphenicol	Prokaryotes	Prevents peptide bond formation by inhibiting peptidyl transferase
4	Cyclohexamide	Eukaryotes	Inhibits peptidyl transferase activity
5	Cephalosporin	Prokaryotic	Inhibits cell wall formation
6	Erythromycin	Prokaryotes	Inhibits translocation of mRNA along ribosome.
7	Neomycin	Prokaryotes	Blocks t RNA-mRNA interaction
8	Penicillin	Prokaryotes	Inhibits cell wall formation
9	Polymyxin	Prokaryotes	Membrane destruction
10	Puromycin	Prokaryotes and Eukaryotes	Induces premature chain termination of a polypeptide
11	Rifampicin	Prokaryotes	Inhibits mRNA synthesis
12	Streptomycin	Prokaryotes	It changes the structure of 30S ribosomal unit which result in misreading of genetic codes of mRNA during translation
13	Tetracycline (broad spectrum)	Prokaryotes	Binds to 30S ribosomal subunit, thus prevents aminoacyl tRNA binding to the ribosome.

14. Novobiocin: 

• It is an aminoglycoside antibiotic.
• An antibiotic compound derived from Streptomyces niveus. 
•  It binds to DNA gyrase, and blocks adenosine triphosphatase (ATPase) activity.
• An inhibitor of bacterial DNA gyrase