<prompt> Termination processor protein synthesis is performed by all except: PGI May 2010Releasing factorStop codonPeptidyl transferaseUAA codon  <response>: Ans: C Peptidyl transferase EAUG codon AUG is initiation codon while UAA,UAG UGA are termination codon- Chatterjea Shinde 7th249-50Peptidyl transferase catalyses peptide bond formation- Harper 28th362In most of cases, AUG acts as initiator codon. AUG also acts as codon for methionine. In a few proteins, GUG may be initiator codon -Vasudevan 5th431Termination Process of Protein Synthesis Vasudevan 5th433After successive addition of AA, ribosome reaches the terminator codon sequence on mRNA. Since there is no tRNA bearing the corresponding anticodon sequence, the A site remains freeReleasing factorRF enters the site along with hydrolysis of GTP to GDP. The RF hydrolyses the peptide chain from the tRNA at P site. The completed peptide chain is now released. Finally 80S ribosome dissociates into its component units of 60S 40S.Materials Required for Protein SynthesisAmino acidsDNA 3 RNAs m-RNA, t-RNA, r-RNAPolyribosomes polysomesQEnzymes: Aminoacyl-t-RNA synthetase, peptidyl transferaseFactorsInitiation facors- IF1 to 3For prokaryotes10 elF elF-1, elF-2, elF-3, elF-4A, elF-4B, e!F-4G, elF- 4E, elf-5Q, for eukaryotesElongation factors-EFl EF2QRelease factors R1 R2Coenzymes cofactors. FH4 Mg2EnergyATP, GTPQ 