1TII:
reference: Crystal structure of a new heat-labile enterotoxin, LT-IIb., van den Akker F, Sarfaty S, Twiddy EM, Connell TD, Holmes RK, Hol WG, Structure 1996 Jun 15;4(6):665-78. PMID: 8805549

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