23S ribosomal RNA

23S Ribosomal RNA

Structure of the 23S rRNA in the E. coli large ribosomal subunit.

Crystal structure of the 23S rRNA.

The 23S ribosomal RNA (23S rRNA) is a component of the 50S ribosomal subunit in prokaryotes. It is a crucial part of the ribosome, which is the molecular machine responsible for protein synthesis in cells. The 23S rRNA is involved in the peptidyl transferase activity of the ribosome, which is the formation of peptide bonds between amino acids during translation.

Structure

The 23S rRNA is a large RNA molecule, typically consisting of about 2900 nucleotides. It folds into a complex three-dimensional structure that is essential for its function. The structure of 23S rRNA includes several helical regions and loops, which interact with ribosomal proteins and other rRNA molecules to form the functional ribosome.

Function

The primary function of the 23S rRNA is to catalyze the formation of peptide bonds, a process known as peptidyl transferase activity. This activity is central to the ribosome's role in translating messenger RNA (mRNA) into polypeptides. The 23S rRNA also plays a role in ensuring the correct alignment of the mRNA and transfer RNA (tRNA) molecules during translation.

Role in Antibiotic Resistance

The 23S rRNA is a target for several classes of antibiotics, including macrolides, lincosamides, and streptogramins. These antibiotics bind to the 23S rRNA and inhibit protein synthesis. Mutations in the 23S rRNA can lead to antibiotic resistance by preventing the binding of these drugs.

Evolutionary Significance

The 23S rRNA is highly conserved across different species of bacteria, making it a valuable tool for phylogenetic studies. Comparisons of 23S rRNA sequences are used to infer evolutionary relationships among bacteria and to identify new species.

Related Pages

• Ribosome
• 16S ribosomal RNA
• 5S ribosomal RNA
• Protein synthesis

Gallery

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  Structure of the 23S rRNA in the E. coli large ribosomal subunit.
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  Crystal structure of the 23S rRNA.