This is a short segment of Z-form DNA
This is a spacefilling model, colored CPK, viewed from the side.
Note the 2 grooves. The major groove is the one in which the phosphates are farther apart. It is non-existent. The minor groove is deep.
The two chains are colored differently. Notice the left-handed twist.
This shows the phosporus colored orange. The zig-zag pattern of the phosphates can be seen in each strand.
An isolated view of several base pairs.