The macrolides (erythromycin, azithromycin, clarithromycin, dirithromycin, troleandomycin, etc.) bind reversibly to the 50S subunit.They can inhibit elongation of the protein by the peptidyltransferase, the enzyme that forms peptide bonds between the amino acids.

Flash animation illustrating The Mode of Action of Macrolides in Blocking Translation during Bacterial Protein Synthesis: Blocking Peptidyltransferase.swf by Gary E. Kaiser, Ph.D.
Professor of Microbiology, The Community College of Baltimore County, Catonsville Campus
This work is licensed under a Creative Commons Attribution 4.0 International License.
Based on a work at http://faculty.ccbcmd.edu/~gkaiser/index.html.

Last updated: August, 2018
Please send comments and inquiries to Dr. Gary Kaiser