| Allowed Value | Details | 
|---|---|
| covale | covalent bond | 
| covale_base | covalent modification of a nucleotide base | 
| covale_phosphate | covalent modification of a nucleotide phosphate | 
| covale_sugar | covalent modification of a nucleotide sugar | 
| disulf | disulfide bridge | 
| hydrog | hydrogen bond | 
| metalc | metal coordination | 
| mismat | mismatched base pairs | 
| modres | covalent residue modification | 
| saltbr | ionic interaction | 
| Allowed Value | Details | 
|---|---|
| covale | covalent bond | 
| covale_base | covalent modification of a nucleotide base | 
| covale_phosphate | covalent modification of a nucleotide phosphate | 
| covale_sugar | covalent modification of a nucleotide sugar | 
| disulf | disulfide bridge | 
| hydrog | hydrogen bond | 
| metalc | metal coordination | 
| mismat | mismatched base pairs | 
| modres | covalent residue modification | 
| saltbr | ionic interaction |