1PMD:
reference: X-ray structure of Streptococcus pneumoniae PBP2x, a primary penicillin target enzyme., Pares S, Mouz N, Petillot Y, Hakenbeck R, Dideberg O, Nat Struct Biol 1996 Mar;3(3):284-9. PMID: 8605631

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