Plasmodium apicoplast 50S ribosomal subunit (Apicoplast 50S ribosome)

The Plasmodium apicoplast 50S ribosomal subunit is a key component of the translation machinery located within the apicoplast, a non-photosynthetic plastid essential for the survival of malaria-causing parasites (Wilson et al., 1996). As the apicoplast is of endosymbiotic origin, its 50S subunit is structurally similar to bacterial ribosomes and significantly different from the human 80S cytosolic ribosome, providing a basis for selective toxicity (Dahl and Rosenthal, 2007). This subunit facilitates the synthesis of proteins required for the maintenance of the apicoplast and its metabolic pathways, such as the non-mevalonate pathway for isoprenoid precursor biosynthesis (Botté et al., 2012). Inhibition of this target by antibiotics like clindamycin or azithromycin disrupts these vital processes, leading to parasite death (Goodman et al., 2007). A unique feature of targeting this subunit is the "delayed death" phenomenon, where the immediate progeny of treated parasites appear viable but fail to survive subsequent replication cycles (Dahl and Rosenthal, 2007). Consequently, drugs hitting this target are often used in combination therapies to ensure rapid clearance of the infection while preventing resistance.

Other names

Apicoplast large ribosomal subunitPlasmodium falciparum apicoplast 50S ribosomeApicoplast 50S subunitApicoplast 50S ribosomal complex

Inhibition of protein synthesis by binding to the 23S rRNA of the 50S ribosomal subunit, thereby blocking the peptidyl transferase center or preventing the translocation of the nascent peptide chain (Dahl and Rosenthal, 2007; Goodman et al., 2007).