A structural motif characteristic of certain proteins that bind to DNA, notably transcription factors. It consists of a finger-like fold of amino acids at the base of which lie two cysteine and two histidine residues. These four residues bind a single zinc ion in a tetrahedral array. Each finger typically interacts with three base pairs in the nucleic acid molecule. Unlike other DNA-binding motifs, such as the helix-turn-helix and the leucine zipper, the zinc finger is also found in proteins that bind to RNA, such as RNA-directed RNA polymerase. Artificially constructed proteins containing arrays of zinc fingers are used as genome editing tools. The amino acid composition of the zinc finger DNA-binding sites is engineered to bind to a target site within the genome of a cell. A nuclease enzyme, introduced with the zinc finger protein as part of an editing module, then cuts both DNA strands at the target site. This can result in gene deletion or integration of newly introduced DNA at the target site, following DNA repair by the cell.