2B48:
reference: BCL-X(L) Dimerization by Three-dimensional Domain Swapping., O'neill JW, Manion MK, Maguire B, Hockenbery DM, J Mol Biol. 2006 Feb 17;356(2):367-81. Epub 2005 Dec 1. PMID: 16368107

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