Each protein chain is represented using 7 lines:
1: Protein ID.
2: Amino acid sequence (from Uniprot sequence).
3: Amino acid sequence (from PDB chain) where . represents a residue that is not present in the PDB chain but is present in the UniProt sequence (inclusion of . is to align this PDB chain to the corresponding UniProt sequence)
4: The DNA-binding annotations where . indicates non-DNA-binding and letters stand for DNA-binding annotations
5: The RNA-binding annotations where . indicates non-RNA-binding and letters stand for RNA-binding annotations
6: The protein-binding annotations where . indicates non-protein-binding and letters stand for protein-binding annotations
7: The ligand-binding annotations where . indicates non-ligand-binding and letters stand for ligand-binding annotations