The reassembling process of the nonameric Mycobacterium tuberculosis small heat-shock protein Hsp16.3 occurs via a stepwise mechanism

Feng, Xiuguang; HUANG, Sufang; Fu, Xinmiao; Abulimiti, Abuduaini; Chang, Zengyi

doi:10.1042/bj3630329

Cited by 6 publications

(3 citation statements)

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“…Small heat shock proteins usually exist as oligomers of variable sizes, ranging from 150 kDa to 800 kDa, with each subunit being 12–42 kDa, and appear to undergo dynamic dissociation/reassociation, with oligomeric dissociation being a prerequisite for their chaperone activities [ 31 ]. sHsp16.3 of M. tuberculosis is reported to form nonamers, which are assembled and reassembled via trimer and hexamer intermediates [ 16 , 32 ]. Native form of this protein was not found to be essential for chaperone activity of the protein [ 33 ].…”

Section: Discussionmentioning

confidence: 99%

Functional characterization of a small heat shock protein from Mycobacterium leprae

et al. 2008

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Background: Small heat shock proteins are ubiquitous family of stress proteins, having a role in virulence and survival of the pathogen. M. leprae, the causative agent of leprosy is an uncultivable organism in defined media, hence the biology and function of proteins were examined by cloning M. leprae genes in heterologous hosts. The study on sHsp18 was carried out as the knowledge about the functions of this major immunodominant antigen of M. leprae is scanty.

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Section: Discussionmentioning

confidence: 99%

Functional characterization of a small heat shock protein from Mycobacterium leprae

et al. 2008

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“…Our previous studies have demonstrated that Hsp16.3 [12,29,37] as well as other molecular chaper ones [38] are able to refold and reassemble after thermal ly or chemically induced denaturation with high efficien cy, and such a property was partially attributed to their high conformation flexibility [28,32]. The observations on the structural characteristics of the G59W mutant pro tein raise a question of whether such a structure disturbed Hsp16.3 protein will still retain its powerful ability to reassemble.…”

Section: Substitution Of the Gly59 Residue Of The Hsp163 Pro Tein Wimentioning

confidence: 99%

Chaperone-Like Activity of Mycobacterium tuberculosis Hsp16.3 Does Not Require Its Intact (Native) Structures

Chen

et al. 2005

Biochemistry (Moscow)

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Small heat shock proteins (sHsps) were found to exhibit efficient chaperone-like activities under stress conditions although their native structures are severely disturbed. Here, using an alternative approach (site-directed mutagenesis), we obtained two structurally and functionally distinct Mycobacterium tuberculosis Hsp16.3 single-site mutant proteins. The G59W mutant protein (with Gly59 substituted by Trp) is capable of exhibiting efficient chaperone-like activity even under non-stress conditions although its secondary, tertiary, and quaternary structures are very different from that of the wild type protein. By contrast, the G59A mutant protein (with Gly59 substituted by Ala) resembles with the wild type protein in structure and function. These observations suggest that the Gly59 of the Hsp16.3 protein is critical for its folding and assembly. In particular, we propose that the exhibition of chaperone-like activity for Hsp16.3 does not require its intact (native) structures but requires the disturbance of its native structures (i.e., the native structure-disturbed Hsp16.3 retains its chaperone-like activity or even becomes more active). In addition, the behavior of such an active mutant protein (G59W) also strongly supports our previous suggestion that Hsp16.3 exhibits chaperone-like activity via oligomeric dissociation.

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“…Transverse urea gradient PAGE ( Figure 3) was performed according to methods described in our previous report [11] . Urea of 6 mol/L concentration was also added in the stacking gel (4% acrylamide, pH 6.8) such that the structure of the disassembly intermediates was maintained.…”

Section: Gel Electrophoresismentioning

confidence: 99%

Disassembly intermediates of RbsD protein remain oligomeric despite the loss of an intact secondary structure

Feng

Zhang

et al. 2009

SCI CHINA SER C

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Many proteins exist as homo-oligomers in living organisms wherein the change of oligomeric status apparently serves as an effective means for modulating their biological activities. We have previously reported that the homo-decameric RbsD from Escherichia coli undergoes stepwise disassembly and non-stepwise reassembly. Here the structural status of the urea-induced RbsD disassembly intermediates was examined, mainly using urea-containing polyacrylamide gel electrophoresis and chemical cross-linking. Such intermediates were found to remain oligomeric while losing their intact secondary structures. Such disassembly intermediates were able to effectively refold when the concentration of the urea denaturant was reduced to a lower level, or to refold/reassemble into the native decamers when urea was completely removed, as detected by non-denaturing polyacrylamide gel electrophoresis. These novel observations strongly suggest that the assembly of oligomeric proteins may occur before the completion of subunit folding.

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The reassembling process of the nonameric Mycobacterium tuberculosis small heat-shock protein Hsp16.3 occurs via a stepwise mechanism

Cited by 6 publications

References 0 publications

Functional characterization of a small heat shock protein from Mycobacterium leprae

Functional characterization of a small heat shock protein from Mycobacterium leprae

Chaperone-Like Activity of Mycobacterium tuberculosis Hsp16.3 Does Not Require Its Intact (Native) Structures

Disassembly intermediates of RbsD protein remain oligomeric despite the loss of an intact secondary structure

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