1AOP:
reference: Sulfite reductase structure at 1.6 A: evolution and catalysis for reduction of inorganic anions., Crane BR, Siegel LM, Getzoff ED, Science 1995 Oct 6;270(5233):59-67. PMID: 7569952

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