1NYA:
reference: NMR solution structure of calerythrin, an EF-hand calcium-binding protein from Saccharopolyspora erythraea., Tossavainen H, Permi P, Annila A, Kilpelainen I, Drakenberg T, Eur J Biochem 2003 Jun;270(11):2505-12. PMID: 12755706

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