These PDBs are individually crystallized receptor and ligand
(unbound/unbound or unbound/bound) used for protein docking 
prediction. They are named by the co_crystallized protein complex
PDB ID which is used to test the prediction. file_r_ro.pdb means
that it is a receptor. file_l_ro.pdb means that it is a ligand.
Their real PDB IDs are specified in
http://zlab.bu.edu/~rong/dock/benchmark.shtml

The only difference of these files with those superposed PDB files
is that the center of the receptor and ligand are translated to the
origin of Cartesian Coordinates. Then, all ligands are randomly
rotated.

Most of the format in these PDB files is the same as that used 
in protein data bank. Four parameters are inserted in some specific
columns for the convinience of protein docking prediction. Column 
numner starts from 0. 

Column 55-56 is the Atomic Contact Energy atom type. The definition
was described in "Zhang C, Vasmatzis G, Cornette JL, and Delisi C, 
Determination of atomic desolvation energies from the structures of 
crystallized proteins. J Mol Biol 1997;267:707-26". For antibodies 
in antibody-antigen complex, constant domains are deleted. All non-CDR
residues are labeled as type 19 in Column 55-56. The method used to 
determine CDR residues from the sequence and secondary structure 
information was specified in 
http://zlab.bu.edu/~rong/dock/cdrlist.html.

Column 62 is a parameter used to specify surface atom or core atom by
computing solvent accessible area. "1" means that it is a surface atom.
"0" means that it is a core atom.

Column 64-67 is the van der Waals radius of this atom from CHARMM 19
parameter set. 

Column 77-81 is the partial charge of this atom from CHARMM 19
potential. The charge of some terminal atoms may need to be corrected.
