4 What are selenocysteine and pyrrolysine How is there incor

4. What are selenocysteine and pyrrolysine? How is there incorporation into proteins regulated?

Solution

Selenocystine is the new 21 protenogenica mino acid which is being developed now..!! It is abbreviated by U.. They contain selenium in their active site. It is coded by a stop codon UGA. As it is encoded by the stop codon hence it regulation is important for incorporation. They contain a cis - forming elements known as sec incorporation sequence present in the 3-UTR in eukaryotes gene which forms a loop or a hair pin structure near the start codon.. Other than that three factors are required to bindi Selenocystine - tRNA,, SPB-2 ELOngation factor & SECIS binding protein

Pyrolysine iss the another new protenogenic amino acids which had been developed. It is found in bacteria and not in human..!!