23S ribosomal RNA of 50S ribosomal subunit (23S rRNA)

Molecular Classification

Ribosomal RNA, Catalytic RNA (ribozyme), Structural RNA, Other

Other Names

23S rRNA, 23S ribosomal RNA, 23S large subunit rRNA, Component of the 50S ribosomal subunit

Disease Roles

Infection (as the bacterial ribosome is essential for pathogen viability and is a common target of antibiotics)Other

23S ribosomal RNA of 50S ribosomal subunit Overview

23S ribosomal RNA is a large, catalytic RNA molecule (~2900 nucleotides in *E. coli*) that forms the core structural and enzymatic component of the 50S large subunit of prokaryotic ribosomes[7][2]. The 23S rRNA is divided into six major structural domains, with domain V harboring the peptidyl transferase center, the main catalytic site for peptide bond formation during protein synthesis[7][2]. This makes 23S rRNA essential for the fundamental process of translation in all bacteria and archaea, and it is the direct target of several classes of antibiotics that inhibit bacterial growth by binding to the peptidyl transferase center or nearby sites[2][7]. Resistance to these antibiotics is often linked to mutations or post-transcriptional modifications within the 23S rRNA sequence. In prokaryotes, 23S rRNA is accompanied by the 5S rRNA and approximately 31 ribosomal proteins to form the full 50S subunit, which associates with the 30S subunit to create the functional 70S ribosome[2][8]. 23S rRNA is not only structurally critical but also functions as a ribozyme, catalyzing the formation of peptide bonds—making it central to life and a validated and clinically exploited antimicrobial target[7][2].

Mechanism of Action

Inhibition of peptide bond formation (peptidyl transferase activity); Interference with ribosomal function to block bacterial protein synthesis; Prevention of tRNA binding or translocation.

Biological Functions

Protein synthesis

Peptidyl transferase activity

Ribosome structural integrity

Disease Associations

Infection (as the bacterial ribosome is essential for pathogen viability and is a common target of antibiotics)

Other

Safety Considerations

Selectivity: Antibiotics targeting 23S rRNA rely on differences between bacterial and human (mitochondrial) ribosomes for safety; cross-reactivity can result in mitochondrial toxicity or side effects
Emergence of resistance: Mutations or methylation in 23S rRNA may confer significant antibiotic resistance

Interacting Drugs

Macrolide antibiotics (e.g., erythromycin, azithromycin)

Chloramphenicol

Lincosamides (e.g., clindamycin)

Oxazolidinones (e.g., linezolid)

Pleuromutilins

Streptogramins

Associated Biomarkers

Biomarker
Mutations in 23S rRNA can be biomarkers for antibiotic resistance (notably for macrolides and related drugs)
Methylation status at specific sites linked to resistance or assembly checkpoints