ALBERT — All Library Books, journals and Electronic Records Telegrafenberg

1

Unbekannt

The structure of natively iodinated bovine thyroglobulin (2021)

Kim, Kookjoo ; Kopylov, Mykhailo ; Bobe, Daija ; [weitere]

International Union of Crystallography

In: Acta Crystallographica Section D: Structural Biology. 2021; 77(11): Published 2021 Oct 29. doi: 10.1107/s2059798321010056.

zur Merkliste hinzufügen auf der Merkliste

Details

Publikationsdatum: 2021-10-29

Beschreibung: Thyroglobulin is a homodimeric glycoprotein that is essential for the generation of thyroid hormones in vertebrates. Upon secretion into the lumen of follicles in the thyroid gland, tyrosine residues within the protein become iodinated to produce monoiodotyrosine (MIT) and diiodotyrosine (DIT). A subset of evolutionarily conserved pairs of DIT (and MIT) residues can then engage in oxidative coupling reactions that yield either thyroxine (T4; produced from coupling of a DIT `acceptor' with a DIT `donor') or triiodothyronine (T3; produced from coupling of a DIT acceptor with an MIT donor). Although multiple iodotyrosine residues have been identified as potential donors and acceptors, the specificity and structural context of the pairings (i.e. which donor is paired with which acceptor) have remained unclear. Here, single-particle cryogenic electron microscopy (cryoEM) was used to generate a high-resolution reconstruction of bovine thyroglobulin (2.3 Å resolution in the core region and 2.6 Å overall), allowing the structural characterization of two post-reaction acceptor–donor pairs as well as tyrosine residues modified as MIT and DIT. A substantial spatial separation between donor Tyr149 and acceptor Tyr24 was observed, suggesting that for thyroxine synthesis significant peptide motion is required for coupling at the evolutionarily conserved thyroglobulin amino-terminus.

Digitale ISSN: 2059-7983

Thema: Chemie und Pharmazie , Geologie und Paläontologie , Physik

Publiziert von International Union of Crystallography

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

AKTUELLE ARTIKEL

S·F·X

Volltext

2

Unbekannt

Crystal structure, Hirshfeld surface and frontier molecular orbital analysis of 9-(3-bromo-4-hydroxy-5-methoxyphenyl)-3,3,6,6-tetramethyl-3,4,5,6,7,9-hexahydro-1H-xanthene-1,8(2H)-dione (2021)

Suresh Babu, N. ; Sughanya, V. ; Praveenkumar, D. ; [weitere]

International Union of Crystallography

In: Acta Crystallographica Section E: Crystallographic Communications. 2021; 77(11): 1170-1174. Published 2021 Oct 29. doi: 10.1107/s2056989021010690.

zur Merkliste hinzufügen auf der Merkliste

Details

Publikationsdatum: 2021-10-29

Beschreibung: In the fused ring system of the title compound, C24H27BrO5, the mean plane and maximum deviations of the central pyran ring are 0.0384 (2) and 0.0733 (2) Å, respectively. The cyclohexenone rings both adopt envelope conformations with the tetra-substituted C atoms as flap atoms, whereas the central pyran ring adopts a flattened boat conformation. The central pyran and phenyl substituent rings are almost perpendicular to each other, making a dihedral angle of 89.71 (2)°. In the crystal, pairs of molecules are linked via O—H...O hydrogen bonds, forming inversion dimers with an R 2 2(20) ring motif. A Hirshfeld surface analysis indicates that the most important contributions to the crystal packing are from H...H (50.6%), O...H/H...O (22.9%) and C...H/H...C (11.1%) contacts. Quantum chemical calculations for the frontier molecular orbitals were undertaken to determine the chemical reactivity of the title compound.

Digitale ISSN: 2056-9890

Thema: Chemie und Pharmazie , Geologie und Paläontologie

Publiziert von International Union of Crystallography

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

AKTUELLE ARTIKEL

S·F·X

Volltext

3

Unbekannt

Crystal structure of N-terminal degron-truncated human glutamine synthetase (2021)

Chek, Min Fey ; Kim, Sun-Yong ; Mori, Tomoyuki ; [weitere]

International Union of Crystallography

In: Acta Crystallographica Section F: Structural Biology Communications. 2021; 77(11): 427-434. Published 2021 Oct 29. doi: 10.1107/s2053230x21010748.

zur Merkliste hinzufügen auf der Merkliste

Details

Publikationsdatum: 2021-10-29

Beschreibung: Glutamine synthetase (GS) is a decameric enzyme that plays a key role in nitrogen metabolism. Acetylation of the N-terminal degron (N-degron) of GS is essential for ubiquitylation and subsequent GS degradation. The full-length GS structure showed that the N-degron is buried inside the GS decamer and is inaccessible to the acetyltransferase. The structure of N-degron-truncated GS reported here reveals that the N-degron is not essential for GS decamer formation. It is also shown that the N-degron can be exposed to a solvent region through a series of conformational adjustments upon ligand binding. In summary, this study elucidated the dynamic movement of the N-degron and the possible effect of glutamine in enhancing the acetylation process.

Digitale ISSN: 2053-230X

Thema: Biologie , Chemie und Pharmazie , Geologie und Paläontologie , Physik

Publiziert von International Union of Crystallography

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

AKTUELLE ARTIKEL

S·F·X

Volltext

4

Unbekannt

On single-crystal total scattering data reduction and correction protocols for analysis in direct space (2021)

Koch, Robert J. ; Roth, Nikolaj ; Liu, Yiu ; [weitere]

International Union of Crystallography

In: Acta Crystallographica Section A: Foundations and Advances. 2021; 77(6): 611-636. Published 2021 Oct 29. doi: 10.1107/s2053273321010159.

zur Merkliste hinzufügen auf der Merkliste

Details

Publikationsdatum: 2021-10-29

Beschreibung: Data reduction and correction steps and processed data reproducibility in the emerging single-crystal total-scattering-based technique of three-dimensional differential atomic pair distribution function (3D-ΔPDF) analysis are explored. All steps from sample measurement to data processing are outlined using a crystal of CuIr2S4 as an example, studied in a setup equipped with a high-energy X-ray beam and a flat-panel area detector. Computational overhead as pertains to data sampling and the associated data-processing steps is also discussed. Various aspects of the final 3D-ΔPDF reproducibility are explicitly tested by varying the data-processing order and included steps, and by carrying out a crystal-to-crystal data comparison. Situations in which the 3D-ΔPDF is robust are identified, and caution against a few particular cases which can lead to inconsistent 3D-ΔPDFs is noted. Although not all the approaches applied herein will be valid across all systems, and a more in-depth analysis of some of the effects of the data-processing steps may still needed, the methods collected herein represent the start of a more systematic discussion about data processing and corrections in this field.

Digitale ISSN: 2053-2733

Thema: Chemie und Pharmazie , Geologie und Paläontologie , Physik

Publiziert von International Union of Crystallography

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

AKTUELLE ARTIKEL

S·F·X

Volltext

5

Unbekannt

Parameterization of magnetic vector potentials and fields for efficient multislice calculations of elastic electron scattering (2021)

Lyon, Keenan ; Rusz, Jan

International Union of Crystallography

In: Acta Crystallographica Section A: Foundations and Advances. 2021; 77(6): 509-518. Published 2021 Oct 29. doi: 10.1107/s2053273321008792.

zur Merkliste hinzufügen auf der Merkliste

Details

Publikationsdatum: 2021-10-29

Beschreibung: The multislice method, which simulates the propagation of the incident electron wavefunction through a crystal, is a well established method for analysing the multiple scattering effects that an electron beam may undergo. The inclusion of magnetic effects into this method proves crucial towards simulating enhanced magnetic interaction of vortex beams with magnetic materials, calculating magnetic Bragg spots or searching for magnon signatures, to name a few examples. Inclusion of magnetism poses novel challenges to the efficiency of the multislice method for larger systems, especially regarding the consistent computation of magnetic vector potentials A and magnetic fields B over large supercells. This work presents a tabulation of parameterized magnetic (PM) values for the first three rows of transition metal elements computed from atomic density functional theory (DFT) calculations, allowing for the efficient computation of approximate A and B across large crystals using only structural and magnetic moment size and direction information. Ferromagnetic b.c.c. (body-centred cubic) Fe and tetragonal FePt are chosen to showcase the performance of PM values versus directly obtaining A and B from the unit-cell spin density by DFT. The magnetic fields of b.c.c. Fe are well described by the PM approach while for FePt the PM approach is less accurate due to deformations in the spin density. Calculations of the magnetic signal, namely the change due to A and B of the intensity of diffraction patterns, show that the PM approach for both b.c.c. Fe and FePt is able to describe the effects of magnetism in these systems to a good degree of accuracy.

Digitale ISSN: 2053-2733

Thema: Chemie und Pharmazie , Geologie und Paläontologie , Physik

Publiziert von International Union of Crystallography

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

AKTUELLE ARTIKEL

S·F·X

Volltext

6

Unbekannt

Vanishing of the atomic form factor derivatives in non-spherical structural refinement – a key approximation scrutinized in the case of Hirshfeld atom refinement (2021)

Midgley, Laura ; Bourhis, Luc J. ; Dolomanov, Oleg V. ; [weitere]

International Union of Crystallography

In: Acta Crystallographica Section A: Foundations and Advances. 2021; 77(6): 519-533. Published 2021 Oct 29. doi: 10.1107/s2053273321009086.

zur Merkliste hinzufügen auf der Merkliste

Details

Publikationsdatum: 2021-10-29

Beschreibung: When calculating derivatives of structure factors, there is one particular term (the derivatives of the atomic form factors) that will always be zero in the case of tabulated spherical atomic form factors. What happens if the form factors are non-spherical? The assumption that this particular term is very close to zero is generally made in non-spherical refinements (for example, implementations of Hirshfeld atom refinement or transferable aspherical atom models), unless the form factors are refinable parameters (for example multipole modelling). To evaluate this general approximation for one specific method, a numerical differentiation was implemented within the NoSpherA2 framework to calculate the derivatives of the structure factors in a Hirshfeld atom refinement directly as accurately as possible, thus bypassing the approximation altogether. Comparing wR 2 factors and atomic parameters, along with their uncertainties from the approximate and numerically differentiating refinements, it turns out that the impact of this approximation on the final crystallographic model is indeed negligible.

Digitale ISSN: 2053-2733

Thema: Chemie und Pharmazie , Geologie und Paläontologie , Physik

Publiziert von International Union of Crystallography

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

AKTUELLE ARTIKEL

S·F·X

Volltext

7

Unbekannt

Prices of IUCr journals (2021)

Ashcroft, A. T.

International Union of Crystallography

In: Acta Crystallographica Section A: Foundations and Advances. 2021; 77(6): 637-638. Published 2021 Oct 29. doi: 10.1107/s2053273321011396.

zur Merkliste hinzufügen auf der Merkliste

Details

Publikationsdatum: 2021-10-29

Digitale ISSN: 2053-2733

Thema: Chemie und Pharmazie , Geologie und Paläontologie , Physik

Publiziert von International Union of Crystallography

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

AKTUELLE ARTIKEL

S·F·X

Volltext

8

Unbekannt

Thyroxine hormones visualized by the cryo-EM structure of bovine thyroglobulin (2021)

Turk, Dušan ; Gunčar, Gregor

International Union of Crystallography

In: Acta Crystallographica Section D: Structural Biology. 2021; 77(11): Published 2021 Oct 29. doi: 10.1107/s2059798321011244.

zur Merkliste hinzufügen auf der Merkliste

Details

Publikationsdatum: 2021-10-29

Digitale ISSN: 2059-7983

Thema: Chemie und Pharmazie , Geologie und Paläontologie , Physik

Publiziert von International Union of Crystallography

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

AKTUELLE ARTIKEL

S·F·X

Volltext

9

Unbekannt

Crystal structures of glycogen-debranching enzyme mutants in complex with oligosaccharides (2021)

Shen, Miaomiao ; Gong, Xiaoxin ; Xiang, Song

International Union of Crystallography

In: Acta Crystallographica Section F: Structural Biology Communications. 2021; 77(11): 420-426. Published 2021 Oct 29. doi: 10.1107/s2053230x21010918.

zur Merkliste hinzufügen auf der Merkliste

Details

Publikationsdatum: 2021-10-29

Beschreibung: Debranching is a critical step in the mobilization of the important energy store glycogen. In eukaryotes, including fungi and animals, the highly conserved glycogen-debranching enzyme (GDE) debranches glycogen by a glucanotransferase (GT) reaction followed by a glucosidase (GC) reaction. Previous work indicated that these reactions are catalyzed by two active sites located more than 50 Å apart and provided insights into their catalytic mechanisms and substrate recognition. Here, five crystal structures of GDE in complex with oligosaccharides with 4–9 glucose residues are presented. The data suggest that the glycogen main chain plays a critical role in binding to the GT and GC active sites of GDE and that a minimum of five main-chain residues are required for optimal binding.

Digitale ISSN: 2053-230X

Thema: Biologie , Chemie und Pharmazie , Geologie und Paläontologie , Physik

Publiziert von International Union of Crystallography

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

AKTUELLE ARTIKEL

S·F·X

Volltext

10

Unbekannt

Syntheses and crystal structures of two copper(I)–halide π,σ-coordination compounds based on 2-[(prop-2-en-1-yl)sulfanyl]pyridine (2021)

Slyvka, Yurii ; Pokhodylo, Nazariy T. ; Goreshnik, Evgeny ; [weitere]

International Union of Crystallography

In: Acta Crystallographica Section E: Crystallographic Communications. 2021; 77(11): 1180-1184. Published 2021 Oct 29. doi: 10.1107/s2056989021011002.

zur Merkliste hinzufügen auf der Merkliste

Details

Publikationsdatum: 2021-10-29

Beschreibung: The title compounds, di-μ-chlorido-bis({2-[(η-2,3)-(prop-2-en-1-yl)sulfanyl]pyridine-κN}copper(I)), [Cu2Cl2(C8H9NS)2], and di-μ-bromido-bis({2-[(η-2,3)-(prop-2-en-1-yl)sulfanyl]pyridine-κN}copper(I)), [Cu2Br2(C8H9NS)2], were obtained by alternating-current electrochemical synthesis starting from an ethanolic solution of 2-[(prop-2-en-1-yl)sulfanyl]pyridine (Psup) and the copper(II) halide. The isostructural crystals are built up from centrosymmetric [Cu2 Hal 2(Psup)2] dimers, which are formed due to the π,σ-chelating behavior of the organic ligand. In the crystals, the dimers are linked by C—H...Hal hydrogen bonds as well as by aromatic π–π stacking interactions into a three-dimensional network.

Digitale ISSN: 2056-9890

Thema: Chemie und Pharmazie , Geologie und Paläontologie

Publiziert von International Union of Crystallography

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

AKTUELLE ARTIKEL

S·F·X

Volltext