The Nucleic Acid Knowledgebase (NAKB), new portal for 3D structural information about Nucleic Acids, is the planned successor to the Nucleic Acid Database (NDB), as described in this recent review:

NAKB provides search, report, statistics, atlas and visualization pages for all nucleic-acid containing experimentally determined 3D structures held by NDB and by the Protein Data Bank (PDB), including all major methods: X-ray, NMR, and Electron Microscopy. For each structure, links are provided to external resources that annotate and analyze nucleic acid structures and their complexes.