From the standpoint of protein dynamics and metalloprotein design, it is interesting to create an artificial protein which induces structural change and regulates its function by metal-ion binding. We engineered a novel protein, "Antennafinger (Ant-F)", whose structure and function can be controlled with Zn(II), by introducing the consensus sequence of a Cys(2)His(2)-type zinc finger protein into a non-metalloprotein scaffold, an Antennapedia homeodomain mutant (Ant-wt), selected using a motif-searching system. The circular dichroism studies demonstrate that Ant-F has secondary structures similar to Ant-wt and also changes its conformation due to Zn(II)-binding. The optical absorption spectra of the Co(II) complexes of Ant-F and its derivative proteins suggest that the geometry of the metal center of holo-Ant-F is tetrahedral and that the mutated Cys(2)His(2) residues are involved in the complex formation. In addition, the gel mobility shift assay reveals that the DNA binding activity of Ant-F can be regulated through Zn(II)-induced structural alteration. These results provide valuable information about the dynamic properties of proteins and a novel concept for metalloprotein design.