zinc finger

https://doi.org/10.1351/goldbook.11391
Small tertiary protein structure in which parts of the protein, typically with cysteine and histidine residues, link to a divalent zinc ion, forming a loop or "finger" that attaches proteins to DNA.
Note: A zinc finger is present in many proteins, such as nucleases or transcription factors that regulate expression of eukaryotic genes.
Source:
PAC, 2016, 88, 713. (Glossary of terms used in developmental and reproductive toxicology (IUPAC Recommendations 2016)) on page 822 [Terms] [Paper]