The present invention relates to a method for screening and discovering bioactive materials using specifically selected protein domains interacting with specific intracellular proteins, and more particularly, to (1) a screening method including confirmation of changes in biological activities by introducing a specific protein domain into microorganisms or animal and plant cells and (2) a screening method including confirmation of changes in biological activities after introducing the specific protein domains into a number of microorganisms or animal and plant cells. Via this method, according to the present invention, it is possible that the selected protein domains can be used to develop novel antibiotic agents with antimicrobial activity effective on bacteria resistant to conventional antibiotics while requiring less genetic information compared with a conventional drug which targets specific genes.