4UWQ:
reference: Structural basis for specificity and promiscuity in a carrier protein/enzyme system from the sulfur cycle., Grabarczyk DB, Chappell PE, Johnson S, Stelzl LS, Lea SM, Berks BC, Proc Natl Acad Sci U S A. 2015 Dec 11. pii: 201506386. PMID: 26655737

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