Let say for this one: http://www.rcsb.org/pdb/explore/explore.do?structureId=3PTA
Is it means that the protein of DNMT1 is bound to DNA molecule? And is the polymer number there (3) is indicating how many structures are there? So, in this case, the number of polymer is stated as 3, meaning that one is protein, and another 2 are for DNA? Is it the correct way of saying the PDB entry?