Interaction of ATP with a Small Heat Shock Protein from Mycobacterium leprae: Effect on Its Structure and Function

Nandi, Sandip K.; Chakraborty, Ayon; Panda, Alok Kumar; Ray, Sougata Sinha; Kar, Rup Kumar; Bhunia, Anirban; Biswas, Ashis

doi:10.1371/journal.pntd.0003661

Cited by 13 publications

(55 citation statements)

References 52 publications

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“…We, for the first time, revealed another functionality of wild-type Hsp16.3, i.e. Among these, surface hydrophobicity is believed to be one of the important factors behind the modulation of the chaperone function of different sHsps under various conditions [9,33,45,46]. We also demonstrated that thermally stressed MDH and ADH retained their enzymatic activity to a larger extent in the presence of C-terminal-truncated mutants (except Hsp16.3DC1 and Hsp16.3DC2) than wild-type Hsp16.3.…”

Section: Discussionmentioning

confidence: 92%

“…We also demonstrated that thermally stressed MDH and ADH retained their enzymatic activity to a larger extent in the presence of C-terminal-truncated mutants (except Hsp16.3DC1 and Hsp16.3DC2) than wild-type Hsp16.3. The surface hydrophobicity of Hsp16.3 as well as other sHsps is mostly probed by bis-ANS, a hydrophobic fluorophore [1,9,33,[45][46][47]. Among these, surface hydrophobicity is believed to be one of the important factors behind the modulation of the chaperone function of different sHsps under various conditions [9,33,45,46].…”

Section: Discussionmentioning

confidence: 99%

“…Apart from exhibiting aggregation prevention ability, many sHsps also play an important role in preventing the inactivation of enzyme activity from thermal stress [44,45]. Whether wild-type Hsp16.3 possesses this ability is still unresolved.…”

Section: Different Substrate Proteins (Insulin and A-lactalbumin)mentioning

confidence: 99%

“…It is well established that surface hydrophobicity governs the chaperone function of different sHsps [9,[45][46][47]. In order to measure the surface hydrophobicity of wild-type and CTE-truncated proteins, a bis-ANS binding study was performed.…”

Section: Surface Hydrophobicity Of Hsp163 Decreases Upon the Truncatmentioning

confidence: 99%

“…Recently, we demonstrated that the dynamics of oligomeric assembly of M. leprae Hsp18 predominates over its static oligomeric assembly in modulating the chaperone function at elevated temperature [45]. The dynamics of oligomeric assembly of many other sHsps including Hsp16.3 is also well known [1,3,12,36].…”

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confidence: 99%

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The C‐terminal extension of Mycobacterium tuberculosis Hsp16.3 regulates its oligomerization, subunit exchange dynamics and chaperone function

et al. 2017

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Mycobacterium tuberculosis is a human pathogen that secretes a major immunodominant antigen, namely Hsp16.3, throughout the course of infection. Hsp16.3 belongs to the small heat shock protein family and exhibits a molecular chaperone function that is important for the growth and survival of M. tuberculosis in host cell macrophages. The importance of the N-terminal region for the structure and chaperone function of Hsp16.3 is well understood. However, the effect of the C-terminal region on these properties is far from clear. Therefore, we cloned, over-expressed and purified wild-type and seven C-terminal-truncated mutant proteins of Hsp16.3. Mutants with deletions of one and two C-terminal extension (CTE) residues had a structure and chaperone function similar to wild-type protein. Intriguingly, deletion of three residues from the CTE triggered perturbation of the tertiary structure, dissociation of the oligomeric assembly (dodecamer to octamer and dimer), enhancement of subunit exchange dynamics and improvement in the chaperone function of Hsp16.3. Interestingly, these structural modulations (except oligomeric dissociation) as well as chaperoning strength reached their apex upon truncation of the entire CTE ( RSTN ). Further deletions from the C-terminal region beyond the CTE increased only the degree of oligomeric dissociation, and the complete removal of this region made the protein into a dimer. Overall, our study suggests a 'new structural element' in the C-terminal region, i.e. the C-terminal extension, which plays an important role in the oligomerization, subunit exchange dynamics and chaperone function of Hsp16.3.

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Section: Discussionmentioning

confidence: 92%

Section: Discussionmentioning

confidence: 99%

Section: Different Substrate Proteins (Insulin and A-lactalbumin)mentioning

confidence: 99%

Section: Surface Hydrophobicity Of Hsp163 Decreases Upon the Truncatmentioning

confidence: 99%

mentioning

confidence: 99%

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The C‐terminal extension of Mycobacterium tuberculosis Hsp16.3 regulates its oligomerization, subunit exchange dynamics and chaperone function

et al. 2017

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Dodecameric structure of a small heat shock protein from Mycobacterium marinum M

et al. 2019

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Small heat shock proteins (sHSPs) are ATP‐independent molecular chaperones present ubiquitously in all kingdoms of life. Their low molecular weight subunits associate to form higher order structures. Under conditions of stress, sHSPs prevent aggregation of substrate proteins by undergoing rapid changes in their conformation or stoichiometry. Polydispersity and dynamic nature of these proteins have made structural investigations through crystallography a daunting task. In pathogens like Mycobacteria, sHSPs are immuno‐dominant antigens, enabling survival of the pathogen within the host and contributing to disease persistence. We characterized sHSPs from Mycobacterium marinum M and determined the crystal structure of one of these. The protein crystallized in three different conditions as dodecamers, with dimers arranged in a tetrahedral fashion to form a closed cage‐like architecture. Interestingly, we found a pentapeptide bound to the dodecamers revealing one of the modes of sHSP‐substrate interaction. Further, we have observed that ATP inhibits the chaperoning activity of the protein.

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The impact of different mutations at arginine141 on the structure, subunit exchange dynamics and chaperone activity of Hsp16.3

et al. 2020

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Hsp16.3, a molecular chaperone, plays a vital role in the growth and survival of Mycobacterium tuberculosis inside the host. We previously reported that deletion of three amino acid residues (142STN144) from C‐terminal extension (CTE) of Hsp16.3 triggers its structural perturbation and increases its chaperone activity, which reaches its apex upon the deletion of its entire CTE (141RSTN144). Thus, we hypothesized that Arg141 (R141) and Ser142 (S142) in the CTE of Hsp16.3 possibly hold the key in maintaining its native‐like structure and chaperone activity. To test this hypothesis, we generated two deletion mutants in which R141 and S142 were deleted individually (Hsp16.3ΔR141 and Hsp16.3ΔS142) and three substitution mutants in which R141 was replaced by lysine (Hsp16.3R141K), alanine (Hsp16.3R141A), and glutamic acid (Hsp16.3R141E), respectively. Hsp16.3ΔS142 or Hsp16.3R141K mutant has native‐like structure and chaperone activity. Deletion of R141 from the CTE (Hsp16.3ΔR141) perturbs the secondary and tertiary structure, lowers the subunit exchange dynamics and decreases the chaperone activity of Hsp16.3. But, the substitution of R141 with alanine (Hsp16.3R141A) or glutamic acid (Hsp16.3R141E) perturbs its secondary and tertiary structure. Surprisingly, such charge tampering of R141 enhances the subunit exchange dynamics and chaperone activity of Hsp16.3. Interestingly, neither the deletion of R141/S142 nor the substitution of R141 with lysine, alanine and glutamic acid affects the oligomeric mass/size of Hsp16.3. Overall, our study suggests that R141 (especially the positive charge on R141) plays a crucial role in maintaining the native‐like structure as well as in regulating subunit exchange dynamics and chaperone activity of Hsp16.3.

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Interaction of ATP with a Small Heat Shock Protein from Mycobacterium leprae: Effect on Its Structure and Function

Cited by 13 publications

References 52 publications

The C‐terminal extension of Mycobacterium tuberculosis Hsp16.3 regulates its oligomerization, subunit exchange dynamics and chaperone function

The C‐terminal extension of Mycobacterium tuberculosis Hsp16.3 regulates its oligomerization, subunit exchange dynamics and chaperone function

Dodecameric structure of a small heat shock protein from Mycobacterium marinum M

The impact of different mutations at arginine141 on the structure, subunit exchange dynamics and chaperone activity of Hsp16.3

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