Mode of Action: Streptomycin acts by inhibiting prokaryote protein synthesis by binding to the S12 protein of the 30S ribosomal subunit, thus preventing the transition from imitation complex to chain-elongating ribosome. This causes miscoding or inhibits initiation.
Mode of Resistance: A mutation in rpsL, a gene for S12 ribosomal protein, prevents binding of streptomycin to the ribosome. An aminoglycoside phosphotransferase also inactivates streptomycin.
Antimicrobial spectrum: Streptomycin acts against gram-negative and gram-positive bacteria.