Need a 3-Dimensional structure of DNA. Get other structures as well by browsing "FirstGlance"

Nature Structural & Molecular Biology’s web site now has a new,
simple tool called FirstGlance in Jmol for visualizing the structures of molecules in three-dimensions:

HYDROLASE/STRUCTURAL PROTEIN 
DNA Double helix (select Jmol viewer)

View the structure of DNA and other structures. Try recognizing these structures from your lecture: 2HHD, 1C8R, 1C4S