Prokaryotic large ribosomal subunit (50S) (50S subunit)

The prokaryotic large ribosomal subunit (50S) is one of two major components of the bacterial ribosome, the site of protein synthesis in all bacteria. It is composed of 23S and 5S ribosomal RNA along with approximately 31–34 different proteins, forming a complex tertiary structure. The primary functions of the 50S subunit are catalyzing peptide bond formation (acting as a ribozyme at the peptidyl transferase center), providing a channel for the nascent polypeptide to exit, and binding various translation factors crucial for elongation, termination, and recycling. Many clinically important antibiotics selectively bind and inhibit the 50S subunit, making it a major validated antimicrobial target. Resistance can develop via target mutations, methylation of rRNA, or alteration in ribosomal proteins. The structural and functional integrity of the 50S subunit is essential for cell viability, and its exclusive features versus the eukaryotic 60S homolog permit therapeutic selectivity for bacterial infections[1][2][3][4][5][7].

Other names

50S ribosomal subunitBacterial large ribosomal subunitRibosome 50S subunitLarge subunit of prokaryotic ribosome

Inhibition of peptide bond formation at the peptidyl transferase center; Blockage of polypeptide exit tunnel; Prevention of ribosomal translocation; Disruption of ribosomal assembly