STRUCT_CONN category. Each type of interaction
is specified in category STRUCT_CONN_TYPE along with the criteria
used to identify interaction. Each interaction listed in STRUCT_CONN
category includes the interaction type, site labels, symmetry operations and
the role of each in the interaction.
The identification of the atoms participating in each interaction is tied to
the labeling information in the ATOM_SITE category.
These relationships are shown in the following diagram.
An abbreviated example of a salt bridge and a hydrogen bond in a protein system.
loop_ _struct_conn_type.id _struct_conn_type.criteria saltbr 'negative to positive distance > 2.5 Angstroms, < 3.2 Angstroms' hydrog 'N-O distance > 2.5 Angstroms, < 3.5 Angstroms, N-O-C angle < 120 degrees' # loop_ _struct_conn.id _struct_conn.conn_type_id _struct_conn.ptnr1_label_comp_id _struct_conn.ptnr1_label_asym_id _struct_conn.ptnr1_label_seq_id _struct_conn.ptnr1_label_atom_id _struct_conn.ptnr1_role _struct_conn.ptnr1_symmetry _struct_conn.ptnr2_label_comp_id _struct_conn.ptnr2_label_asym_id _struct_conn.ptnr2_label_seq_id _struct_conn.ptnr2_label_atom_id _struct_conn.ptnr2_role _struct_conn.ptnr2_symmetry C1 saltbr ARG A 87 NZ1 positive 1_555 GLU A 92 OE1 negative 1_555 C2 hydrog ARG B 287 N donor 1_555 GLY B 292 O acceptor 1_555
Another abbreviated example illustrating the description of hydrogen bonding in a DNA duplex structure.
loop_ _struct_conn_type.id _struct_conn_type.criteria hydrog ; N - O distance > 2.5 Angstroms and < 3.5 Angstroms N - O - C angle < 120 degrees ; loop_ _struct_conn.id _struct_conn.conn_type_id _struct_conn.ptnr1_label_comp_id _struct_conn.ptnr1_label_asym_id _struct_conn.ptnr1_label_seq_id _struct_conn.ptnr1_label_atom_id _struct_conn.ptnr1_symmetry _struct_conn.ptnr2_label_comp_id _struct_conn.ptnr2_label_asym_id _struct_conn.ptnr2_label_seq_id _struct_conn.ptnr2_label_atom_id _struct_conn.ptnr2_symmetry _struct_conn.details 1 hydrog T A 1 N3 1_555 A A 6 N1 8_555 WATSON-CRICK 2 hydrog T A 1 O4 1_555 A A 6 N6 8_555 WATSON-CRICK 3 hydrog G A 2 N2 1_555 C A 5 O2 8_555 WATSON-CRICK 4 hydrog G A 2 N1 1_555 C A 5 N3 8_555 WATSON-CRICK 5 hydrog G A 2 O6 1_555 C A 5 N4 8_555 WATSON-CRICK 6 hydrog G A 3 N2 1_555 C A 4 O2 8_555 WATSON-CRICK loop_ _atom_site.id _atom_site.label_atom_id _atom_site.label_comp_id _atom_site.label_asym_id _atom_site.label_seq_id _atom_site.label_entity_id _atom_site.cartn_x _atom_site.cartn_y _atom_site.cartn_z _atom_site.occupancy _atom_site.B_iso_or_equiv 1 O5* T A 1 1 -18.744 20.195 22.722 1.00 36.68 2 C5* T A 1 1 -18.262 20.915 23.867 1.00 4.63 3 C4* T A 1 1 -16.837 20.481 24.110 1.00 5.29