Enzyme involved in peptide chain synthesis is

Peptide band formation : The alpha aminogroup at the incoming aminoacid in the "A"site forms a peptide bond (CO-NH0 with carboxyl group of the peptidyl tRNA occuping the "P" site.This reaction is catalyzed by the enzyme peptidyltransferase (28S rRNA,a component of 60S subunit). This is an example of ribozyme; RNA acts as the enzyme. Since, the aminoacid brought in by the tRNA is already activated,there is no need for futher energy supply for the purpose of peptidebond formation. Now, the growing peptide chain is occuping the "A" site. REF : DM VASUDEVAN TEXTBOOK ,7th EDITION ,Page no: 601.