The strongly conserved carboxyl‐terminus glycine‐methionine motif of the <i>Escherichia coli</i> GroEL chaperonin is dispensable

McLennan, Neil; Girshovich, A.S.; Lissin, Nikolai; Charters, Y. M.; Masters, Millicent

doi:10.1111/j.1365-2958.1993.tb01096.x

Cited by 67 publications

(49 citation statements)

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“…Its structure is not resolved in the X-ray crystals suggesting a flexible conformation. Deletion of the entire repeat region in GroEL has indicated that it is dispensable, although deletion had some effect on ATPase activity and the ability to suppress temperature-sensitive mutations (Mclennan et al 1993). Moreover, a recent study showed that replacement of the methionine residues by alanine decelerated folding of a mutant maltose binding protein (Tang et al 2006).…”

Section: Discussionmentioning

confidence: 99%

Single-nucleotide variations in the genes encoding the mitochondrial Hsp60/Hsp10 chaperone system and their disease-causing potential

Bross

Hansen

et al. 2006

J Hum Genet

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Molecular chaperones assist protein folding, and variations in their encoding genes may be disease-causing in themselves or influence the phenotypic expression of disease-associated or susceptibility-conferring variations in many different genes. We have screened three candidate patient groups for variations in the HSPD1 and HSPE1 genes encoding the mitochondrial Hsp60/Hsp10 chaperone complex: two patients with multiple mitochondrial enzyme deficiency, 61 sudden infant death syndrome cases (MIM: #272120), and 60 patients presenting with ethylmalonic aciduria carrying non-synonymous susceptibility variations in the ACADS gene (MIM: *606885 and #201470). Besides previously reported variations we detected six novel variations: two in the bidirectional promoter region, and one synonymous and three non-synonymous variations in the HSPD1 coding region. One of the non-synonymous variations was polymorphic in patient and control samples, and the rare variations were each only found in single patients and absent in 100 control chromosomes. Functional investigation of the effects of the variations in the promoter region and the non-synonymous variations in the coding region indicated that none of them had a significant impact. Taken together, our data argue against the notion that the chaperonin genes play a major role in the investigated diseases. However, the described variations may represent genetic modifiers with subtle effects.

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Section: Discussionmentioning

confidence: 99%

Single-nucleotide variations in the genes encoding the mitochondrial Hsp60/Hsp10 chaperone system and their disease-causing potential

Bross

Hansen

et al. 2006

J Hum Genet

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“…This is consistent with the hypothesis that the bsubunit is adapted to a higher temperature than the asubunit. The a-subunit may be the prototype from which the b-subunit has evolved, because it has the GGM repeat sequence that is conserved in group I chaperonin (McLennan et al, 1993;Brocchieri and Karlin, 2000) and in some chaperonins of archaea belonging to Euryarchaeota (Kuo et al, 1997;Yoshida et al, 1997;Furutani et al, 1998). The a-subunit might have been lost after the divergence of the Pyrococcus species from the Thermococcus species.…”

Section: Discussionmentioning

confidence: 99%

Natural chaperonin of the hyperthermophilic archaeum, Thermococcus strain KS-1: a hetero-oligomeric chaperonin with variable subunit composition

Yoshida¹,

Ideno²,

Hiyamuta³

et al. 2001

Mol Microbiol

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SummaryTo study the difference in expression of the chaperonin a-and b-subunits in Thermococcus strain KS-1 (T. KS-1), we measured their intracellular contents at various growth temperatures using subunit-specific antibodies. The b-subunit was significantly more abundant with increasing temperature (maximum at 938C), whereas the a-subunit was not. Native PAGE with Western blot analysis indicated that the natural chaperonins in the crude extracts of T. KS-1 cells grown between 658C and 958C migrate as single bands with different mobility. The recombinant a-and b-subunit homo-oligomers migrated differently from each other and from natural chaperonins. Immunoprecipitation also showed that the natural chaperonin was the hetero-oligomer. These results indicate that chaperonin in T. KS-1 formed a hetero-oligomer with variable subunit composition, and that the b-subunit may be adapted to a higher temperature than the asubunit. T. KS-1 probably changes its chaperonin subunit composition to acclimatize to the ambient temperature.

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“…For this it is important to note that the prokaryotic chaperonin GroEL has long hydrophobic tails at its C terminus that are not resolved in the crystal structure (32). This hydrophobic surface may interact with solvent in such a way as to affect Fig.…”

Section: Discussionmentioning

confidence: 99%

Protein folding under confinement: A role for solvent

Lucent

Vishal²,

Pande

2007

Proc. Natl. Acad. Sci. U.S.A.

154

149

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Although most experimental and theoretical studies of protein folding involve proteins in vitro, the effects of spatial confinement may complicate protein folding in vivo. In this study, we examine the folding dynamics of villin (a small fast folding protein) with explicit solvent confined to an inert nanopore. We have calculated the probability of folding before unfolding (Pfold) under various confinement regimes. Using Pfold correlation techniques, we observed two competing effects. Confining protein alone promotes folding by destabilizing the unfolded state. In contrast, confining both protein and solvent gives rise to a solvent-mediated effect that destabilizes the native state. When both protein and solvent are confined we see unfolding to a compact unfolded state different from the unfolded state seen in bulk. Thus, we demonstrate that the confinement of solvent has a significant impact on protein kinetics and thermodynamics. We conclude with a discussion of the implications of these results for folding in confined environments such as the chaperonin cavity in vivo.chaperonin mechanism ͉ explicit solvent ͉ distributed computing ͉ molecular dynamics H ow proteins fold into a unique native structure is an important unanswered question. There have been a number of experiments and computer simulations that have provided insight into the mechanism by which folding occurs (1, 2). Most of these experiments and simulations measure the dynamics of proteins in infinite dilution. However, bulk solvent is different from the cellular environment in which proteins truly fold. In vivo, protein dynamics occur in the context of the crowded cellular milieu and in confined spaces such as the chaperonin cavity, the proteosome, the ribosome exit tunnel, the translocon, etc. When considering these factors it is reasonable to assume that proteins may experience different energy landscapes when folding in vivo than in bulk, and these differences may constitute a significant piece of the folding puzzle.Confinement has been previously treated both analytically and via simulation using polymer physics models (3-10). These models predict that by excluding more extended structures confinement reduces the conformational entropy of the unfoldedstate ensemble. This restriction leads to the relative stabilization of the folded state. These models are in qualitative accord with recent experiments that have shown accelerated folding of small proteins in chaperonin mutants possessing decreased cavity volume (11). Despite the elegance and intuitiveness of these models, they omit details that may be important when thinking of folding in vivo.For example, it is known that solvent plays a critical role in protein folding, as most of the free energy for folding comes from maximizing solvent entropy (because of the molecular nature of hydrophobicity). Polymer models for confined folding do not consider the effect of confinement on the solvent and its subsequent effects on protein stability. Although explicit solvent complicates analytical models a...

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The strongly conserved carboxyl‐terminus glycine‐methionine motif of the Escherichia coli GroEL chaperonin is dispensable

Cited by 67 publications

References 50 publications

Single-nucleotide variations in the genes encoding the mitochondrial Hsp60/Hsp10 chaperone system and their disease-causing potential

Single-nucleotide variations in the genes encoding the mitochondrial Hsp60/Hsp10 chaperone system and their disease-causing potential

Natural chaperonin of the hyperthermophilic archaeum, Thermococcus strain KS-1: a hetero-oligomeric chaperonin with variable subunit composition

Protein folding under confinement: A role for solvent

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