Bacterial 70S ribosome (Cutibacterium acnes) (C. acnes 70S ribosome)

The 70S ribosome of Cutibacterium acnes is the essential ribonucleoprotein complex responsible for translating genetic information into functional proteins within this Gram-positive bacterium (Lomakin et al., 2023). As a key driver of the inflammatory skin condition acne vulgaris, the C. acnes ribosome serves as a critical therapeutic target for various classes of antibiotics, including macrolides and tetracyclines (Bunick et al., 2024). Recent cryo-electron microscopy studies have revealed a unique secondary binding site located within the nascent peptide exit tunnel (NPET) near the peptidyl transferase center (PTC) of the 50S subunit (Lomakin et al., 2023; ResearchGate, 2023). This site is specifically targeted by sarecycline, a narrow-spectrum tetracycline, which utilizes a novel two-site mechanism to inhibit protein synthesis (PNAS, 2020; bioRxiv, 2025). Unlike traditional tetracyclines that primarily bind the 30S decoding center, sarecycline also occupies this secondary site in the 50S subunit, interacting with actinobacteria-specific ribosomal proteins like bL37 (Lomakin et al., 2023). This interaction sterically blocks the passage of the growing polypeptide chain, leading to potent and selective antimicrobial activity against C. acnes while minimizing effects on the gut microbiome (PMC, 2021).

Other names

Propionibacterium acnes 70S ribosomeC. acnes ribosome70S ribosome (Cutibacterium acnes)Bacterial ribosome

Inhibition of protein synthesis via a two-site mechanism involving the mRNA decoding center (30S) and the nascent peptide exit tunnel (50S) near the peptidyl transferase center (Lomakin et al., 2023).