The taming of small heat-shock proteins: crystallization of the α-crystallin domain from human Hsp27

Small heat-shock proteins (sHsps) are ubiquitous molecular chaperones. sHsps function as homooligomers or heterooligomers that are prone to subunit exchange and structural plasticity. Here, a procedure for obtaining diffraction-quality crystals of the alpha-crystallin domain of human Hsp27 is presented. Initially, limited proteolysis was used to delineate the corresponding stable fragment (residues 90-171). This fragment could be crystallized, but examination of the crystals using X-rays indicated partial disorder. The surface-entropy reduction approach was applied to ameliorate the crystal quality. Consequently, a double mutant E125A/E126A of the 90-171 fragment yielded well ordered crystals that diffracted to 2.0 A resolution. journal: Acta Crystallographica Section F: Structural Biology and Crystallization Communications content_type: crystallization communications peer_reviewed: Yes review_process: Single blind received: 31 August 2009 accepted: 26 October 2009 published_online: 27 November 2009 copyright: © 2009 International Union of Crystallography ispartof: Acta Crystallographica F, Structural Biology and Crystallization Communications Online vol:65 issue:Pt 12 pages:1277-1281 ispartof: location:England status: published