2KIL:
reference: A structural basis for H-NOX signaling in Shewanella oneidensis by trapping a histidine kinase inhibitory conformation., Erbil WK, Price MS, Wemmer DE, Marletta MA, Proc Natl Acad Sci U S A. 2009 Nov 24;106(47):19753-60. Epub 2009 Nov 16. PMID: 19918063

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