Ancient Protein KsgA and its FunctionsAuthor(s): Nima Kizaki
Ribosome biogenesis is a multistep process that occurs in all organisms. The processing of ribosomal RNA (rRNA) from a primary transcript, as well as the modification of rRNAs and ribosomal proteins (r-proteins) and the connection of rproteins with rRNA, necessitates a high level of coordination and a slew of other components. The result of this process is the formation of a functional ribosome from two distinct ribosomal subunits that join together during translation initiation. In general, a simplified ribosome biogenesis strategy seems to be indicative of the process throughout evolution. The nucleotide modification level of ribosome biogenesis indicates significant differences in the ribosome maturation process between prokaryotes, eukaryotes, and archaea. Only three rRNA changes, in particular, are retained across all three kingdoms. In large ribosomal subunit (LSU) rRNA, one example is the conversion of U1958 (Escherichia coli numbering) to pseudouridine. While the alteration itself is universal, the machinery and thus the technique by which it is performed vary by kingdom and organism.