Helix 69 of the 23S ribosomal RNA (H69) (H69)

Helix 69 (H69) is a highly conserved 19-nucleotide hairpin loop located in Domain IV of the 23S ribosomal RNA (rRNA) within the bacterial 50S ribosomal subunit (PMID: 17113994). It serves as a primary component of the intersubunit bridge B2a, which is essential for the association of the 30S and 50S subunits to form a functional 70S ribosome (PMID: 11012831). Beyond structural stability, H69 plays a dynamic role in protein synthesis, participating in the translocation of tRNA from the A-site to the P-site and interacting with various translation factors (PMID: 15575965). Its high level of sequence and structural conservation across diverse bacterial pathogens makes it a significant target for the development of broad-spectrum antibiotics. Certain classes of antibiotics, such as tuberactinomycins (e.g., viomycin and capreomycin), exert their antimicrobial effects by binding to the ribosomal interface at H69, thereby inhibiting translocation and subunit dissociation (PMID: 15575965). Research into H69-targeted ligands continues to be a promising avenue for addressing the global challenge of multi-drug resistant bacterial infections (PMID: 22103475).

Other names

Helix 69H69 region of 23S rRNA23S rRNA helix 69Intersubunit bridge B2a componentBacterial 50S ribosomal subunit helix 69

Inhibition of translocation and stabilization of the intersubunit bridge B2a, preventing the conformational changes required for protein synthesis (PMID: 15575965).