Antibiotic binding sites on the large and small subunits of the ribosome identified by crystallographic means. Small subunits (30S and 40S) are shown in blue and large subunits (50S and 60S) are shown in grey. The two most common drug targets are located in the small subunit decoding site (paromomycin, gentamicin and neomycin) and in the large subunit peptidyl transferase center (sparsomycin, chloramphenicol, puromycin, linezolid, clindamycin and erythromycin). The PDB accession codes for the structures are: 3R8O 3R8T, 3O30 and 3O5H.