3BJ8:
reference: The crystal structure of spermidine/spermine N1-acetyltransferase in complex with spermine provides insights into substrate binding and catalysis., Montemayor EJ, Hoffman DW, Biochemistry. 2008 Sep 2;47(35):9145-53. Epub 2008 Aug 9. PMID: 18690703

This OCA Structure page
uses Jmol, developed by the Jmol Development Team (documentation).