DNA-binding domains are specific regions within proteins that interact directly with DNA. These domains enable proteins to recognize and bind to particular sequences of DNA, playing a crucial role in processes such as gene regulation, replication, and repair. Common types of DNA-binding domains include zinc fingers, helix-turn-helix, and leucine zippers. The ability of DNA-binding domains to attach to DNA is essential for the function of many proteins, including transcription factors and enzymes. By binding to DNA, these proteins can influence the expression of genes, ensuring that the right proteins are produced at the right times in response to cellular signals.