6BBT:
reference: Group A Streptococcus T-antigens have a highly conserved structure concealed under a heterogeneous surface that has implications for vaccine design., Young PG, Raynes JM, Loh JM, Proft T, Baker EN, Moreland NJ, Infect Immun. 2019 Apr 1. pii: IAI.00205-19. doi: 10.1128/IAI.00205-19. PMID: 30936156

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