<entity chain_ids="A" class="protein" count="1" entity_id="1" source_entry="2SRT" type="polymer"/>
<entity chain_ids="B,C" class="ligand" count="2" entity_id="2" source_entry="2SRT" type="non-polymer"/>
<entity chain_ids="D" class="ligand" count="1" entity_id="3" source_entry="2SRT" type="non-polymer"/>