3AR4:
reference: Trinitrophenyl derivatives bind differently from parent adenine nucleotides to Ca2+-ATPase in the absence of Ca2+, Toyoshima C, Yonekura SI, Tsueda J, Iwasawa S, Proc Natl Acad Sci U S A. 2011 Jan 14. PMID: 21239683

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