1NLA:
reference: Solution structure of switch Arc, a mutant with 3(10) helices replacing a wild-type beta-ribbon., Cordes MH, Walsh NP, McKnight CJ, Sauer RT, J Mol Biol 2003 Feb 21;326(3):899-909. PMID: 12581649

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