Zinc finger proteins are a family of nucleic acid-binding proteins that have a specific protein domain: the zinc finger domain. Here, a zinc ion (Zn2+) is coordinately bound. Due to the incorporation of the zinc atom, the polypeptide chain adopts a loop-shaped structure - the so-called zinc finger - which can interact specifically with DNA or even RNA.
Zinc finger proteins have at least one zinc finger domain that folds around a central zinc ion The zinc ion is responsible for stabilizing even relatively small portions of a polypeptide bond so that they can interact with nucleic acids. Since zinc has only one stable oxidation state, it also cannot catalyze unwanted reactions within the cell.
The zinc finger domain is a domain that binds mainly to DNA, so zinc finger proteins are usually transcription factors. RNA-binding zinc finger proteins are also known. Zinc finger proteins also include receptors for steroid hormones.