Bi-and Poly-Functional Enzymes
These enzymes are generated by genes obtained by fusion of the coding regions of two or more genes encoding various enzymes. In simple words, the strategy for generation of such enzymes is as follows. Consider gene a produces enzyme A and gene b create enzyme B, and for some reason it is desirable to bring the two enzyme activities together. The stop codon, e.g. TAG, of gene is removed, and that changed gene a is then connected with the initiation codon or TAG of gene b. It required, a linker sequence encoding 2-10 amino acids can be started between the genes b and a. It is required that the fusion of the two genes does not modify the reading frame of gene b, i.e. the two genes are refused in the general reading frame. The fused gene will give a single polypeptide which can possess/exhibit the activities of both the enzymes B and A.