3X39:
reference: Domain-Swapped Dimer of Pseudomonas aeruginosa Cytochrome c551: Structural Insights into Domain Swapping of Cytochrome c Family Proteins., Nagao S, Ueda M, Osuka H, Komori H, Kamikubo H, Kataoka M, Higuchi Y, Hirota S, PLoS One. 2015 Apr 8;10(4):e0123653. doi: 10.1371/journal.pone.0123653., eCollection 2015. PMID: 25853415

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