1NKF:
reference: Alpha-helix nucleation by a calcium-binding peptide loop., Siedlecka M, Goch G, Ejchart A, Sticht H, Bierzyski A, Proc Natl Acad Sci U S A 1999 Feb 2;96(3):903-8. PMID: 9927666

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