A brief summary of the role of DnaK and GroE chaperones in protein folding precedes a discussion of the role of GroE in Escherichia coli. We consider its obligate substrates, the 8 that are both obligate and essential, and the prospects for constructing a mutant that could survive without it. Structural features of GroE-dependent polypeptides are also considered.
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http://dx.doi.org/10.1016/j.resmic.2009.04.002 | DOI Listing |
mSphere
January 2025
Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
Unlabelled: During infection, bacterial pathogens rely on secreted virulence factors to manipulate the host cell. However, in gram-positive bacteria, the molecular mechanisms underlying the folding and activity of these virulence factors after membrane translocation are not clear. Here, we solved the protein structures of two secreted parvulin and two secreted cyclophilin-like peptidyl-prolyl isomerase (PPIase) ATP-independent chaperones found in gram-positive streptococcal species.
View Article and Find Full Text PDFActa Naturae
January 2024
St Petersburg University, St. Petersburg, 199034 Russian Federation.
Living organisms exhibit an impressive ability to expand the basic information encoded in their genome, specifically regarding the structure and function of protein. Two basic strategies are employed to increase protein diversity and functionality: alternative mRNA splicing and post-translational protein modifications (PTMs). Enzymatic regulation is responsible for the majority of the chemical reactions occurring within living cells.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China; Shandong Energy Institute, Qingdao 266101, China; Qingdao New Energy Shandong Laboratory, Qingdao 266101, China. Electronic address:
Metamorphic proteins switch reversibly between distinctly different folds often with different functions under physiological conditions. Here, the kinetics and thermodynamics of the fold-switching at different temperatures in a metamorphic protein, KaiB, involved in cyanobacterial circadian clock, reveal that enthalpy-driven the fold-switching to form fold-switched KaiB (fsKaiB) and the fsKaiB and ground-state KaiB (gsKaiB) are more dominantly at lower and higher temperatures, respectively. Thermodynamic analysis indicates that conformational and solvent entropy have opposing effects on KaiB's fold-switching.
View Article and Find Full Text PDFJ Neurochem
January 2025
Centre for Prions and Protein Folding Diseases, University of Alberta, Edmonton, Canada.
Highly abundant in neurons, the cellular prion protein (PrP) is an obligatory precursor to the disease-associated misfolded isoform denoted PrP that accumulates in the rare neurodegenerative disorders referred to either as transmissible spongiform encephalopathies (TSEs) or as prion diseases. The ability of PrP to serve as a substrate for this template-mediated conversion process depends on several criteria but importantly includes the presence or absence of certain endoproteolytic events performed at the cell surface or in acidic endolysosomal compartments. The major endoproteolytic events affecting PrP are referred to as α- and β-cleavages, and in this review we outline the sites within PrP at which the cleavages occur, the mechanisms potentially responsible and their relevance to pathology.
View Article and Find Full Text PDFProtein Sci
February 2025
MOE Key Laboratory of Bioinformatics, School of Life Sciences, Tsinghua University, Beijing, China.
An important step of mainstream protein structure prediction is to model the 3D protein structure based on the predicted 2D inter-residue geometric information. This folding step has been integrated into a unified neural network to allow end-to-end training in state-of-the-art methods like AlphaFold2, but is separately implemented using the Rosetta folding environment in some traditional methods like trRosetta. Despite the inferiority in prediction accuracy, the conventional approach allows for the sampling of various protein conformations compatible with the predicted geometric constraints, partially capturing the dynamic information.
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