A protein synthesis inhibitor is a compound that stops or slows the growth or proliferation of cells by disrupting the processes that lead directly to the generation of new proteins. While a broad interpretation of this definition could be used to describe nearly any compound depending on concentration, in practice, it usually refers to compounds that act at the molecular level on translational machinery (either the ribosome itself or the translation factor), taking advantages of the major differences between prokaryotic and eukaryotic ribosome structures.

Mechanism

In general, protein synthesis inhibitors work at different stages of bacterial mRNA translation into proteins, like initiation, elongation (including aminoacyl tRNA entry, proofreading, peptidyl transfer, and bacterial translocation) and termination:

Earlier stages

Initiation

Ribosome assembly

Aminoacyl tRNA entry

Proofreading

Peptidyl transfer

Ribosomal translocation

Termination

Protein synthesis inhibitors of unspecified mechanism

Binding site

The following antibiotics bind to the 30S subunit of the ribosome: The following antibiotics bind to the 50S ribosomal subunit: