In a study involving a cell free protein synthesizing system from E.coli, the po
ID: 71989 • Letter: I
Question
In a study involving a cell free protein synthesizing system from E.coli, the poly ribonucleotide AUGUUUUUUUUUUUU directs the synthesis of the oligopeptide fMet-Phe-Phe-Phe-Phe. In the presence of Rambomycin, a new antibiotic just developed by Macho Pharmaceuticals, only the dipeptide fMet-Phe is made.
A) What step in polypeptide synthesis does the antibiotic inhibit? Explain.
B) Will the oligopeptide product be found attached to tRNA at the end of uninhited reaction? Will the dipeptide be found attached to tRNA at the end of the Rambomycin-inhibited reaction? Explain.
Explanation / Answer
Form the given data,
The synthesis of protein form an mRNA by the enzyme peptidyl transferase (ribosomes) is called translation or protein synthesis. Ribosomes are the cellular particles, which are present in both prokaryotic and eukaryotic cells.
They are composed of two sub units, and each sub unit is a combination of protein and rRNA (ribosomal RNA). The main function of ribosomes is protein synthesis. The protein synthesis takes place in three main steps, namely
A)
The antibiotic Rambomycin inhabits the elongation step of protein synthesis. This is because the already two amino acids are synthesized in the peptide.
B)
Yes, the oligopeptide product be found attached to tRNA at the end of uninhited reaction. No, the dipeptide cannot be found attached to tRNA at the end of the Rambomycin-inhibited reaction. This is because the Rambomycin probably inhibit the enzyme peptidyl transferase, so newly coming amino acid cannot be added to the already synthesized protein. So, the previously formed protein detach from tRNA.