2HMX:
reference: Three-dimensional structure of the human immunodeficiency virus type 1 matrix protein., Massiah MA, Starich MR, Paschall C, Summers MF, Christensen AM, Sundquist WI, J Mol Biol 1994 Nov 25;244(2):198-223. PMID: 7966331

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