| 1. |
- Hoencamp, Claire, et al.
(författare)
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3D genomics across the tree of life reveals condensin II as a determinant of architecture type
- 2021
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 372:6545, s. 984-989
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Tidskriftsartikel (refereegranskat)abstract
- We investigated genome folding across the eukaryotic tree of life. We find two types of three-dimensional (3D) genome architectures at the chromosome scale. Each type appears and disappears repeatedly during eukaryotic evolution. The type of genome architecture that an organism exhibits correlates with the absence of condensin II subunits. Moreover, condensin II depletion converts the architecture of the human genome to a state resembling that seen in organisms such as fungi or mosquitoes. In this state, centromeres cluster together at nucleoli, and heterochromatin domains merge. We propose a physical model in which lengthwise compaction of chromosomes by condensin II during mitosis determines chromosome-scale genome architecture, with effects that are retained during the subsequent interphase. This mechanism likely has been conserved since the last common ancestor of all eukaryotes.
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| 2. |
- Nechushtai, Rachel, et al.
(författare)
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Allostery in the ferredoxin protein motif does not involve a conformational switch
- 2011
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Science Sessions. - 0027-8424 .- 1091-6490. ; 108:6, s. 2240-2245
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Tidskriftsartikel (refereegranskat)abstract
- Regulation of protein function via cracking, or local unfolding and refolding of substructures, is becoming a widely recognized mechanism of functional control. Oftentimes, cracking events are localized to secondary and tertiary structure interactions between domains that control the optimal position for catalysis and/or the formation of protein complexes. Small changes in free energy associated with ligand binding, phosphorylation, etc., can tip the balance and provide a regulatory functional switch. However, understanding the factors controlling function in single-domain proteins is still a significant challenge to structural biologists. We investigated the functional landscape of a single-domain plant-type ferredoxin protein and the effect of a distal loop on the electron-transfer center. We find the global stability and structure are minimally perturbed with mutation, whereas the functional properties are altered. Specifically, truncating the L1,2 loop does not lead to large-scale changes in the structure, determined via X-ray crystallography. Further, the overall thermal stability of the protein is only marginally perturbed by the mutation. However, even though the mutation is distal to the iron-sulfur cluster (∼20 Å), it leads to a significant change in the redox potential of the iron-sulfur cluster (57 mV). Structure-based all-atom simulations indicate correlated dynamical changes between the surface-exposed loop and the iron-sulfur cluster-binding region. Our results suggest intrinsic communication channels within the ferredoxin fold, composed of many short-range interactions, lead to the propagation of long-range signals. Accordingly, protein interface interactions that involve L1,2 could potentially signal functional changes in distal regions, similar to what is observed in other allosteric systems.
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| 3. |
- Schug, Alexander, et al.
(författare)
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From protein folding to protein function and biomolecular binding by energy landscape theory
- 2010
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Ingår i: Current opinion in pharmacology (Print). - : Elsevier Ltd. - 1471-4892 .- 1471-4973. ; 10:6, s. 709-714
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Tidskriftsartikel (refereegranskat)abstract
- Protein folding and function are inherently linked sharing a joined funneled energy landscape. In this theoretical framework, the integration of simulations, structural information, and sequence data has led to quantitatively explore, understand, and predict biomolecular binding and recognition, key processes in pharmacology, as a natural extension of the selective self-binding found in protein folding. Computer simulations based on these principles have made valuable contributions to understanding protein and RNA folding, protein-protein interactions, and protein-metabolite/RNA-metabolite interactions.
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