Data items in the NDB_STRUCT_CONF_NA category describes secondary structure features in this entry.
loop_ _ndb_struct_conf_na.entry_id _ndb_struct_conf_na.feature _ndb_struct_conf_na.feature_count rcsb000001 'double helix' 1 rcsb000001 'b-form double helix' 1 rcsb000001 'quadruple helix' 1