<prompt> About peptidyl transferase true is:Used in elongation and cause attachment of peptide chain to A-site of tRNAUsed in elongation and cause attachment peptide chain to P siteUsed in initiation and cause 43S complex formationUsed in initiation and cause 48S complex formation  <response>: Ans. A. Used in elongation and cause attachment of peptide chain to A-site of tRNARef: Harper 31e page 403The 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. 