The key feature of DNA that allows it to replicate is its double helix structure. This configuration, consisting of two intertwined strands, enables the separation of the strands during the replication process. Each strand serves as a template for the synthesis of a new complementary strand, facilitated by the enzyme DNA polymerase. The base pairing rules (adenine with thymine, and cytosine with guanine) ensure accurate replication, which is vital for cell division and the passing of genetic information to subsequent generations.