2DLN:
reference: Vancomycin resistance: structure of D-alanine:D-alanine ligase at 2.3 A resolution., Fan C, Moews PC, Walsh CT, Knox JR, Science 1994 Oct 21;266(5184):439-43. PMID: 7939684

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