This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Molecular Genetics, Subject name: Biochemistry
[{'content': 'About peptidyl transferase true is: \nSelect and explain. \nA. Used in elongation and cause attachment of peptide chain to A-site of tRNA, B. Used in elongation and cause attachment peptide chain to P site, C. Used in initiation and cause 43S complex formation, D. Used in initiation and cause 48S complex formation', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. A. Used in elongation and cause attachment of peptide chain to A-site of tRNA(Ref: Harper 31/e page 403)The a amino group of the new aminoacyl-tRNA in the A site carries out a nucleophilic attack on the esterified carboxyl group of the peptidyl-tRNA occupying the P site (peptidyl or polypeptide site). At initiation, this site is occupied by the initiator met-tRNAi.This reaction is catalyzed by a peptidyl transferase, a component of the 28S RNA of the 60S ribosomal subunit.This is another example of ribozyme activity.', 'role': 'assistant'}]