PROTEIN DATABASE                                                                                                             http://www.rcsb.org/pdb/home/home.do

The PDB (Protein Data Bank) archive is a repository of atomic coordinates and other information describing proteins and other important biological macromolecules. The PDB give the information of three dimensional structural biology. 

Select which one of the topic you want, then start to exploring. The Structural View of Biology interface starts with key topic categories and subcategories that drill down to individual molecules.

The PDB also share a video to help you to understanding about the 3D shape and the function of macromolecules.