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

• Published in: Acta crystallographica. Section F, Structural biology and crystallization communications Structural biology and crystallization communications, 2009-12, Vol.65 (12), p.1277-1281
• Main Authors: Baranova, E. V., Beelen, S., Gusev, N. B., Strelkov, S. V.
• Format: Article
• Language: English
• Subjects: alpha-Crystallins - chemistry; alpha-Crystallins - genetics; Amino Acid Sequence; Cloning, Molecular; Crystallization Communications; Crystallography, X-Ray; Hsp27; HSP27 Heat-Shock Proteins - chemistry; HSP27 Heat-Shock Proteins - genetics; Humans; molecular chaperones; Molecular Sequence Data; Mutagenesis; Peptide Fragments - chemistry; Peptide Fragments - genetics; Protein Conformation; Protein Structure, Tertiary; Recombinant Proteins - chemistry; Recombinant Proteins - genetics; Sequence Homology, Amino Acid; small heat-shock proteins; α-crystallin domains
• ISSN: 1744-3091; 1744-3091
• DOI: 10.1107/S1744309109044571

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 α‐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 Å resolution.