Chemical diagram of Watson-Crick base-pairs

Once in awhile, I need to refresh my memory about the chemical identities of the most common nucleobases: A, C, G, T/U. Sometimes, it is also necessary to explain to non-(bio)chemists about the concept of H-bond donor vs acceptor, and the major- vs minor-groove of the DNA double helix. In such cases, I use the following (customized) chemical diagram of Waton-Crick base-pairs (WC-bp):


Before taking the effort to create my own version of the Waton-Crick base-pair diagram, I googled around and found many illustrations (like the one in wikipedia). However, none of them suits my needs perfectly:

• Trained as a chemist, I would like to see chemical bond types (double vs. single bond);
  
• Working extensively with PDB format, I want to have the atom numbering information as well.

So I ended up to (re)create my own version of the WC-bp diagram: I used Chemtool to sketch the framework, and Xfig to fine-tune it. Overall, the diagram serves my purpose quite well, and hopefully others would find it useful as well.