zincfingerproteiner

Zinc finger proteins are a large superfamily of proteins characterized by the presence of zinc finger motifs, small structural modules stabilized by a bound zinc ion. The most common motif, the C2H2 zinc finger, consists of about 30 amino acids that coordinate a Zn2+ ion through two cysteine residues and two histidine residues, forming a compact fold that presents a DNA-binding surface. Proteins may contain one or many fingers in tandem, enabling recognition of longer DNA sequences.

Zinc finger domains can bind DNA, RNA, or other proteins. In DNA-binding zinc finger proteins, arrays of fingers recognize specific DNA sequences; each finger typically contacts several base pairs, enabling modular design. ZFPs play roles in transcriptional regulation, development, differentiation, and other cellular processes. The zinc ion stabilizes the finger fold and contributes to binding specificity. There are other classes such as C3H1, C2HC, and RING fingers, which mediate diverse interactions, including ubiquitination, RNA binding, and protein-protein interactions.

Applications and engineering: The concept of zinc finger nucleases (ZFNs) combines engineered zinc finger arrays with a nucleolytic domain (usually FokI) to induce targeted double-strand breaks for genome editing. ZFPs have been used in research and biotechnology, though newer technologies such as CRISPR-Cas have largely superseded them for many applications.

Discovery and evolution: The zinc finger motif was identified in the 1980s in transcription factors such as TFIIIA from Xenopus laevis, with the structure solved by X-ray crystallography. Zinc finger proteins are widespread in eukaryotes and are essential for numerous regulatory networks; misregulation can be linked to diseases.