Title:The taming of small heat-shock proteins: crystallization of the alpha-crystallin domain from human Hsp27.
Authors:Baranova EV; Beelen S; Gusev NB; Strelkov SV
Publication:Acta Crystallogr Sect F Struct Biol Cryst Commun. 2009 Dec 1;65(Pt 12):1277-81. doi: 10.1107/S1744309109044571. Epub 2009 Nov 27.
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.