1GTK:
reference: Time-resolved and static-ensemble structural chemistry of hydroxymethylbilane synthase., Helliwell JR, Nieh YP, Habash J, Faulder PF, Raftery J, Cianci M, Wulff M, Hadener A, Faraday Discuss. 2003;122:131-44; discussion 171-90. PMID: 12555854

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