Practice question

Genetic, biochemical, and crystallographic studies established that peptide bond formation is catalyzed by ribosomal RNA, not protein side chains. The peptidyl transferase center resides within domain V of large subunit 23S rRNA in prokaryotes, conserved as 28S rRNA in eukaryotes, where nucleotides position the 3' CCA ends of P-site and A-site tRNAs for nucleophilic attack of amino group on ester carbonyl. Key adenine A2451 contributes orientation and pKa perturbation rather than direct acid-base chemistry. Deproteinized large subunit retains catalytic activity, demonstrating the ribosome is a true ribozyme, the largest natural RNA catalyst with synthetic polymerase activity known.