Which ribosomal subunit does clindamycin act on and how does it affect protein synthesis?

Clindamycin acts on the 50S ribosomal subunit and inhibits peptidyl transferase activity. By binding to this subunit, clindamycin disrupts the normal function of the ribosome during the protein synthesis process. Specifically, it prevents the formation of peptide bonds between amino acids, which is a crucial step in building polypeptide chains. This inhibition effectively stops the elongation of the nascent protein, leading to a reduction in protein synthesis.

The choice indicating that clindamycin inhibits translocation is close but not entirely accurate since clindamycin's primary action is on the peptidyl transferase aspect of protein synthesis. Understanding the specific mechanisms involved is important in recognizing how antibiotics target bacterial ribosomes, as well as how they differ in their actions from other classes of antibiotics that may affect other subunits or processes in the protein synthesis pathway.