Non-canonical amino acid incorporation via genetic code reprogramming in a cell-free translation system

Non-canonical amino acids (ncAAs) and unnatural amino acids (UAAs) both holds the characteristic features of the amino acids but lacks functional role in the protein synthesis. The ncAAs and UAAs possess unique chemical, physical or biological properties other than the 20 standard amino acids (canonical amino acid) used by the cell system, imparting novel functions in the cell when incorporated into the proteins. Genetic code reprograming (GCR) is a unique technique which would allow to expand the basic building blocks in addition to the natural 20 amino acids. Rewiring of the genetic code allows site-specific incorporation of these ncAAs/UAAs to target protein and impart the novel properties with a commercial value to the target protein. Roles and potential applications of ncAAs and the UAAs have been discussed in detail with relevant findings significant to the protein engineering and appliations in this chapter.