From Proteopedia

This article gives step by step instructions for uploading an atomic coordinate file (a "molecule" or PDB file) for use in molecular scenes in Proteopedia.

Don't upload files available from www.pdb.org

If the molecule you want to display is available from the Protein Data Bank, you don't need to upload it. In the load molecule dialog of the Molecular Scene Authoring Tools (SAT), simply give the PDB code, and Proteopedia will obtain the PDB file for you.