Related Experiment Video
Updated: May 3, 2026
08:42
Visual and Microscopic Evaluation of Streptomyces Developmental Mutants
Published on: September 12, 2018
19.9K
The structural basis of yeast prion strain variants
Brandon H Toyama1, Mark J S Kelly, John D Gross
1Howard Hughes Medical Institute, Department of Cellular and Molecular Pharmacology, University of California San Francisco and California Institute for Quantitative Biomedical Research, San Francisco, California 94158-2542, USA.
Nature
|September 4, 2007
Summary
Prion strains, like yeast Sup35 Sc4 and Sc37, exhibit distinct structures. These large-scale conformational differences in prion proteins explain their varying stability and replication, impacting disease phenotypes.
Area of Science:
- Biochemistry
- Structural Biology
- Prion Biology
Background:
- Prion biology is characterized by the strain phenomenon, where single proteins misfold into distinct infectious states causing different phenotypes.
- Understanding the structural basis of these prion strains and their physiological impact is limited.
Purpose of the Study:
- To investigate the structural differences between two yeast Sup35 prion strains, Sc4 and Sc37.
- To elucidate how these structural variations influence prion stability and replication.
Main Methods:
- Solution NMR
- Amide hydrogen/deuterium (H/D) exchange
- Mutagenesis
Main Results:
- Both Sc4 and Sc37 strains share a common amyloid core in the first 40 amino acids, protected from H/D exchange and sensitive to mutation.
- The Sc37 conformation expands this stable structure to the first 70 amino acids, correlating with increased fiber stability and reduced chaperone-mediated replication.
- Prion strains involve significant conformational differences, providing a structural basis for their varied functional and physiological impacts.
Conclusions:
- Prion strains arise from large-scale conformational variations within the protein structure.
- These structural differences directly influence prion stability, replication efficiency, and ultimately, the observed disease phenotypes.
Related Concept Videos
01:29Cytoskeletal Proteins in Bacteria
3.5K
Bacterial cells were initially considered simple, randomly organized structures lacking a cytoskeleton. However, the discovery of cytoskeleton homologs in bacteria led to the change of this opinion. Bacterial cytoskeletal filaments regulate the cell shape, cell polarity, cell division, and partitioning of plasmids during cell division. It was later discovered that bacterial cytoskeletal proteins, mainly actin and tubulin homologs, are diverse compared to their eukaryotic counterparts. On the...
3.5K
01:29Microbial Morphologies
4.8K
Bacterial and archaeal cells exhibit remarkable diversity in shape and structure, critical in their adaptability and functionality. Among bacteria, the most commonly observed shapes include cocci and bacilli. Cocci are spherical and may exist singly or in groupings such as pairs (diplococci), chains (streptococci), clusters (staphylococci), or tetrads. Bacilli, in contrast, are rod-shaped and can also occur as single cells, in pairs, or chains, depending on their environmental and genetic...
4.8K
01:20Endospores and Sporulation
6.8K
Endospores are specialized, dormant cells primarily formed by Gram-positive bacteria, including Bacillus and Clostridium, enabling survival under extreme environmental conditions. Due to their unique composition and formation process, these structures are highly resistant to physical and chemical insults, such as extreme heat, ultraviolet and ionizing radiation, desiccation, and toxic chemicals. Rare instances of endospore-like structures have also been observed in some Gram-negative bacteria,...
6.8K
01:30Bacterial Phylum Actinobacteria
854
Coryneform bacteria are gram-positive, aerobic, nonmotile rods that exhibit irregular, club-shaped, or V-shaped arrangements. Their V-shape results from snapping division, where the inner cell wall layer forms the cross-wall, while the outer layer remains intact until it ruptures on one side, causing the daughter cells to bend away.The primary genera are Corynebacterium and Arthrobacter. Corynebacterium includes diverse species, ranging from saprophytes to pathogens like Corynebacterium...
854
01:24Bacterial Phylum Tenericutes
673
The phylum Tenericutes, which includes the single class Mollicutes, comprises bacteria that lack cell walls. The term "Mollicutes" derives from the Latin word mollis, meaning "soft." These organisms are among the smallest known and are commonly referred to as mycoplasmas due to the prominence of the genus Mycoplasma, which includes well-known human pathogens. Despite their inability to stain gram-positively (a result of their lack of cell walls), mycoplasmas are phylogenetically related to the...
673
01:29Microbes in Food Production
403
Microbial fermentation is central to food biotechnology, enhancing flavor, texture, preservation, and stability. Fermentative microorganisms metabolize carbohydrates into organic acids, alcohols, and other metabolites that inhibit spoilage organisms and improve digestibility while contributing distinctive sensory qualities.In baking, amylases naturally present in flour hydrolyze starch into monosaccharides such as glucose, which Saccharomyces cerevisiae ferments anaerobically. Through...
403