TER

Overview

The TER record indicates the end of a list of ATOM/HETATM records for a chain.

Record Format

COLUMNS         DATA TYPE         FIELD        DEFINITION
-------------------------------------------------------------------------
 1 -  6         Record name       "TER   "

 7 - 11         Integer           serial       Serial number.

18 - 20         Residue name      resName      Residue name.

22              Character         chainID      Chain identifier.

23 - 26         Integer           resSeq       Residue sequence number.

27              AChar             iCode        Insertion code.

Details

* Every chain of ATOM/HETATM records presented on SEQRES records is terminated with a TER record.

* The TER records occur in the coordinate section of the entry, and indicate the last residue presented for each polypeptide and/or nucleic acid chain for which there are coordinates. For proteins, the residue defined on the TER record is the carboxy-terminal residue; for nucleic acids it is the 3'-terminal residue.

* For a cyclic molecule, the choice of termini is arbitrary.

* Terminal oxygen atoms are presented as OXT for proteins, and as O5T or O3T for nucleic acids.

* The TER record has the same residue name, chain identifier, sequence number and insertion code as the terminal residue. The serial number of the TER record is one number greater than the serial number of the ATOM/HETATM preceding the TER.

* For chains with gaps due to disorder, it is recommended that the C-terminus atoms be labelled O and OXT, and a REMARK explaining the ambiguity be provided.

Verification/Validation/Value Authority Control

TER must appear at the end carboxy or 3' of a chain. For proteins, there is usually a terminal oxygen, labeled OXT. The validation program checks for the occurrence of TER and OXT records.

Relationships to Other Record Types

The residue name appearing on the TER record must be the same as the residue name of the immediately preceding ATOM or non-water HETATM record.

Example

         1         2         3         4         5         6         7         8
12345678901234567890123456789012345678901234567890123456789012345678901234567890
ATOM   4150  H   ALA A 431       8.674  16.036  12.858  1.00  0.00           H
TER    4151      ALA A 431

ATOM   1403  O   PRO P  22      12.701  33.564  15.827  1.09 18.03           O
ATOM   1404  CB  PRO P  22      13.512  32.617  18.642  1.09  9.32           C
ATOM   1405  CG  PRO P  22      12.828  33.382  19.740  1.09 12.23           C
ATOM   1406  CD  PRO P  22      12.324  34.603  18.985  1.09 11.47           C
HETATM 1407  CA  BLE P   1      14.625  32.240  14.151  1.09 16.76           C
HETATM 1408  CB  BLE P   1      15.610  33.091  13.297  1.09 16.56           C
HETATM 1409  CG  BLE P   1      15.558  34.629  13.373  1.09 14.27           C
HETATM 1410  CD1 BLE P   1      16.601  35.208  12.440  1.09 14.75           C
HETATM 1411  CD2 BLE P   1      14.209  35.160  12.930  1.09 15.60           C
HETATM 1412  N   BLE P   1      14.777  32.703  15.531  1.09 14.79           N
HETATM 1413  B   BLE P   1      14.921  30.655  14.194  1.09 15.56           B
HETATM 1414  O1  BLE P   1      14.852  30.178  12.832  1.09 16.10           O
HETATM 1415  O2  BLE P   1      13.775  30.147  14.862  1.09 20.95           O
TER    1416      BLE P   1