Final answer:
Zinc-finger domains are common DNA-binding domains found in various proteins. They play a role in regulating gene expression.
Step-by-step explanation:
The zinc-finger domain is a common type of DNA-binding domain found in various proteins. It consists of a cluster of amino acids, including cysteine and histidine, which form a zinc ion binding site. Zinc-finger domains are important for DNA recognition and binding, and they play a role in regulating gene expression.
Examples of proteins that contain zinc-finger domains include transcription factors like thyroid hormone receptors and WRKY transcription factors.