Crystallization and preliminary X-ray diffraction analysis of XAC1151, a small heat-shock protein from<i>Xanthomonas axonopodis</i>pv.<i>citri</i>belonging to the α-crystallin family

Hilario, E.; Teixeira, Elaine Cristina; Pedroso, Gisele Audrei; Bertolini, Maria Célia; Medrano, F.J.

doi:10.1107/s174430910601219x

Cited by 13 publications

(14 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This finding is supported by the observation of sulphate ions accumulated at the dimer interface in recent crystal structures [48,156]. Mapping changes in residue-specific protease susceptibility of aB-crystallin upon the addition of nucleotide [157] on the structure of the core domain suggest that the location of the sulphate may represent ATP-binding sites [53].…”

Section: Shsp Activity Is Influenced By Environmental Conditionssupporting

confidence: 61%

Small Heat-Shock Proteins: Paramedics of the Cell

Hilton

Lioe

Stengel

et al. 2012

Topics in Current Chemistry

123

129

View full text Add to dashboard Cite

The small heat-shock proteins (sHSPs) comprise a family of molecular chaperones which are widespread but poorly understood. Despite considerable effort, comparatively few high-resolution structures have been determined for the sHSPs, a likely consequence of their tendency to populate ensembles of inter-converting conformational and oligomeric states at equilibrium. This dynamic structure appears to underpin the sHSPs' ability to bind and sequester target proteins rapidly, and renders them the first line of defence against protein aggregation during disease and cellular stress. Here we describe recent studies on the sHSPs, with a particular focus on those which have provided insight into the structure and dynamics of these proteins. The combined literature reveals a picture of a remarkable family of molecular chaperones whose thermodynamic and kinetic properties are exquisitely balanced to allow functional regulation by subtle changes in cellular conditions.

show abstract

Section: Shsp Activity Is Influenced By Environmental Conditionssupporting

confidence: 61%

Small Heat-Shock Proteins: Paramedics of the Cell

Hilton

Lioe

Stengel

et al. 2012

Topics in Current Chemistry

123

129

View full text Add to dashboard Cite

show abstract

“…We achieved crystallization by removing 59 and 68 N-terminal residues and 10 and 13 C-terminal residues from AAC and ABC, respectively (Table I) Tsp36, 34 and HspA. 33 More generally, the overall architecture is similar to the beta and gamma crystallin double greek key motif. 36 In the AAC and ABC 68-162 structures, one side of the beta sandwich consists of three beta strands that form an antiparallel beta sheet interaction at the dimer interface, which we term the AP interface.…”

Section: Resultsmentioning

confidence: 99%

“…[27][28][29][30] The structures reported here extend the information provided by the structures of Bagneris et al 26 They offer electron density for the important residues 151-157, which the ABC 67-157 structure lacks, and also offer the structure of the highly conserved C-terminal tail sequence IPI/V, which illuminates one factor in maintenance of lens transparency. Related structures of other members of the small heat shock protein (sHSP) family [15][16][17] have been determined: for Wheat Hsp16.9 (WhHsp16.9), 31 Methanococcus janaschii Hsp16.5 (MjHsp16.5), 32 Xanthomonas axonopodis HspA, 33 and Metazoan Tsp36. 34 The structure of the conserved C-terminal extension that we find important for enforcing polydispersity has been observed only in WhHsp16.9 31 and MjHsp16.5.…”

Section: Introductionmentioning

confidence: 99%

Crystal structures of truncated alphaA and alphaB crystallins reveal structural mechanisms of polydispersity important for eye lens function

et al. 2010

View full text Add to dashboard Cite

Small heat shock proteins alphaA and alphaB crystallin form highly polydisperse oligomers that frustrate protein aggregation, crystallization, and amyloid formation. Here, we present the crystal structures of truncated forms of bovine alphaA crystallin (AAC ) and human alphaB crystallin (ABC 68-162 ), both containing the C-terminal extension that functions in chaperone action and oligomeric assembly. In both structures, the C-terminal extensions swap into neighboring molecules, creating runaway domain swaps. This interface, termed DS, enables crystallin polydispersity because the C-terminal extension is palindromic and thereby allows the formation of equivalent residue interactions in both directions. That is, we observe that the extension binds in opposite directions at the DS interfaces of AAC 59-163 and ABC . A second dimeric interface, termed AP, also enables polydispersity by forming an antiparallel beta sheet with three distinct registration shifts. These two polymorphic interfaces enforce polydispersity of alpha crystallin. This evolved polydispersity suggests molecular mechanisms for chaperone action and for prevention of crystallization, both necessary for transparency of eye lenses.Keywords: X-ray diffraction; small heat shock protein; protein chaperone; desmin-related myopathy; cataract; eye lens transparency Abbreviations: AAC 59-163 , alphaA crystallin residues 59-163; AAC 59-163 -Zn, zinc-bound alphaA crystallin residues 59-163; ABC 68-162 , alphaB crystallin residues 68-162; ABC 68-157 , alphaB crystallin residues 68-157; ABC 67-157 , alphaB crystallin residues 67-157; ADH, alcohol dehydrogenase; AP, antiparallel beta sheet interface; AP x , antiparallel beta sheet registration state x; DS, domain-swapped interface; Hsp20 65-162 , rat heat shock protein 20 residues 65-162; MjHsp16.5, Methanococcus janaschii heat shock protein 16.5; MS, mass spectrometry; sHSP, small heat shock protein; WhHsp16.9, wheat heat shock protein 16.9.Additional Supporting Information may be found in the online version of this article.

show abstract

“…His6-tagged HspA protein (His6HspA) was expressed and purified as described previously. 37 In order to produce the non-fusion protein, we amplified the HspA gene from the plasmid construction pET28a-HspA using specific oligonucleotides primers, in which the insertion at the NdeI and BamHI restriction sites of the expression vector pET-3a (Novagen) was allowed. The entire polynucleotide sequence was confirmed.…”

Section: Experimental Procedures Protein Expression and Purificationmentioning

confidence: 99%

Crystal Structures of Xanthomonas Small Heat Shock Protein Provide a Structural Basis for an Active Molecular Chaperone Oligomer

Hilario

Martin

Bertolini

et al. 2011

Journal of Molecular Biology

Self Cite

View full text Add to dashboard Cite

Small heat shock proteins (sHsps) are ubiquitous low-molecular-weight chaperones that prevent protein aggregation under cellular stresses. sHsps contain a structurally conserved α-crystallin domain (ACD) of about 100 amino acid residues flanked by varied N- and C-terminal extensions and usually exist as oligomers. Oligomerization is important for the biological functions of most sHsps. However, the active oligomeric states of sHsps are not defined yet. We present here crystal structures (up to 1.65 Å resolution) of the sHspA from the plant pathogen Xanthomonas (XaHspA). XaHspA forms closed or open trimers of dimers (hexamers) in crystals but exists predominantly as 36mers in solution as estimated by size-exclusion chromatography. The XaHspA monomer structures mainly consist of α-crystallin domain with disordered N- and C-terminal extensions, indicating that the extensions are flexible and not essential for the formation of dimers and 36mers. Under reducing conditions where α-lactalbumin (LA) unfolds and aggregates, XaHspA 36mers formed complexes with one LA per XaHspA dimer. Based on XaHspA dimer-dimer interactions observed in crystals, we propose that XaHspA 36mers have four possible conformations, but only XaHspA 36merB, which is formed by open hexamers in 12mer-6mer-6mer-12mer with protruding dimers accessible for substrate (unfolding protein) binding, can bind to 18 reduced LA molecules. Together, our results unravel the structural basis of an active sHsp oligomer.

show abstract

Crystallization and preliminary X-ray diffraction analysis of XAC1151, a small heat-shock protein fromXanthomonas axonopodispv.citribelonging to the α-crystallin family

Cited by 13 publications

References 15 publications

Small Heat-Shock Proteins: Paramedics of the Cell

Small Heat-Shock Proteins: Paramedics of the Cell

Crystal structures of truncated alphaA and alphaB crystallins reveal structural mechanisms of polydispersity important for eye lens function

Crystal Structures of Xanthomonas Small Heat Shock Protein Provide a Structural Basis for an Active Molecular Chaperone Oligomer

Contact Info

Product

Resources

About