1HWT:
reference: Structure of a HAP1-DNA complex reveals dramatically asymmetric DNA binding by a homodimeric protein., King DA, Zhang L, Guarente L, Marmorstein R, Nat Struct Biol 1999 Jan;6(1):64-71. PMID: 9886294

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