3CR8:
reference: Structure of the two-domain hexameric APS kinase from Thiobacillus denitrificans: structural basis for the absence of ATP sulfurylase activity., Gay SC, Segel IH, Fisher AJ, Acta Crystallogr D Biol Crystallogr. 2009 Oct;65(Pt 10):1021-31. Epub 2009, Sep 16. PMID: 19770499

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