List of PDB IDs for the family 5_3_exonuc
1XO1B|188-274
1EXNA|188-274
1XO1A|188-274
1UT8A|188-274
1UT5B|188-274
1UT5A|188-274
1UT8B|188-274
1EXNB|188-274
1TAQA|174-271
1BGXT|174-271
1TAUA|174-271