RNF8-FHA domain modified protein and a method of manufacturing the same

No intramolecular disulfide bonds, which itself provides an antigen binding protein obtained only in vitro selection method using RNF8-FHA domain that functions in a cell. 1-4 pieces of loops extending from the FHA domain randomized, artificially created in the FHA domain surface recognition sites to the target molecule, to build RNF8-FHA domain library. Using the library, select efficiently antigen-binding protein in vitro. .FIELD 1