What is the structure of DNA and who discovered it?

DNA is a double helix structure consisting of two antiparallel strands of nucleotides connected by hydrogen bonds between complementary base pairs (A-T with 2 bonds, G-C with 3 bonds). James Watson and Francis Crick proposed this model in 1953, building on X-ray crystallography data from Rosalind Franklin. The sugar-phosphate backbone runs on the outside while the bases face inward, creating major and minor grooves important for protein binding.