The Crystal Structure of Indole-3-glycerol Phosphate Synthase from the Hyperthermophilic ArchaeonSulfolobus solfataricusin Three Different Crystal Forms: Effects of Ionic Strength

Two new structures of semisynthetic ergot alkaloid terguride created by unusual number of symmetry-independent molecules were determined by X-ray diffraction methods at 150 K. Form A (monoclinic, P212121, Z = 12) contains three symmetry-independent terguride molecules and two molecules of water in the asymmetric part of the unit cell. The form CA (monoclinic, P21, Z = 8) is an anhydrate remarkable by the presence of four symmetry-independent molecules in the crystal structure. Conformations of twelve symmetry-independent molecules that were found in four already described terguride structures are compared with torsion angles obtained by ab initio quantum-mechanical calculations for the simplified model of N-cyclohexyl-N'-diethylurea.

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Crystal structure of phenylalanine-regulated 3-deoxy-D-arabino-heptulosonate-7-phosphate synthase from Escherichia coli

Structure ◽

10.1016/s0969-2126(99)80109-9 ◽

1999 ◽

Vol 7 (7) ◽

pp. 865-875 ◽

Cited By ~ 79

Author(s):

Igor A Shumilin ◽

Robert H Kretsinger ◽

Ronald H Bauerle

Keyword(s):

Crystal Structure ◽

Escherichia Coli ◽

Phosphate Synthase

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A novel inhibitor of indole-3-glycerol phosphate synthase with activity against multidrug-resistant Mycobacterium tuberculosis

FEBS Journal ◽

10.1111/j.1742-4658.2008.06763.x ◽

2008 ◽

Vol 276 (1) ◽

pp. 144-154 ◽

Cited By ~ 21

Author(s):

Hongbo Shen ◽

Feifei Wang ◽

Ying Zhang ◽

Qiang Huang ◽

Shengfeng Xu ◽

...

Keyword(s):

Mycobacterium Tuberculosis ◽

Multidrug Resistant ◽

Glycerol Phosphate ◽

Phosphate Synthase

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Minimizing Polymorphic Risk Through Cooperative Computational and Experimental Exploration

10.26434/chemrxiv.12546389.v1 ◽

2020 ◽

Author(s):

Christopher R. Taylor ◽

Matthew T. Mulvee ◽

Domonkos S. Perenyi ◽

Michael R. Probert ◽

Graeme Day ◽

...

Keyword(s):

Crystal Structure ◽

High Pressure ◽

Structure Prediction ◽

Experimental Approach ◽

Significant Risk ◽

Free Energy Calculations ◽

Crystal Structure Prediction ◽

Crystal Forms ◽

Wide Range ◽

Solid Form

<div> <p>We combine state-of-the-art computational crystal structure prediction (CSP) techniques with a wide range of experimental crystallization methods to understand and explore crystal structure in pharmaceuticals and minimize the risk of unanticipated late-appearing polymorphs. Initially, we demonstrate the power of CSP to rationalize the difficulty in obtaining polymorphs of the well-known pharmaceutical isoniazid and show that CSP provides the structure of the recently discovered, but unsolved, Form III of this drug despite there being only a single known form for almost 70 years. More dramatically, our blind CSP study predicts a significant risk of polymorphism for the related iproniazid. Employing a wide variety of experimental techniques, including high-pressure experiments, we experimentally obtained the first three known non-solvated crystal forms of iproniazid, all of which were successfully predicted in the CSP procedure. We demonstrate the power of CSP methods and free energy calculations to rationalize the observed elusiveness of the third form of iproniazid, the success of high-pressure experiments in obtaining it, and the ability of our synergistic computational-experimental approach to “de-risk” solid form landscapes.</p> </div>

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Crystal Structure of Two Crystal Forms of 9α-Fluorocortisol Acetate: Variation of the Conformation of the A Ring of Steroids Due to Crystal Packing

Journal of Pharmaceutical Sciences ◽

10.1002/jps.2600760316 ◽

1987 ◽

Vol 76 (3) ◽

pp. 253-258 ◽

Cited By ~ 2

Author(s):

Paul A. Sutton ◽

Stephen R. Byrn

Keyword(s):

Crystal Structure ◽

Crystal Packing ◽

Crystal Forms

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Structure of the plant photosystem I

Biochemical Society Transactions ◽

10.1042/bst20170299 ◽

2018 ◽

Vol 46 (2) ◽

pp. 285-294 ◽

Cited By ~ 18

Author(s):

Ido Caspy ◽

Nathan Nelson

Keyword(s):

Crystal Structure ◽

Photosystem I ◽

Excitation Energy Transfer ◽

Transmembrane Helices ◽

Iron Sulfur Clusters ◽

Crystal Forms ◽

Light Harvesting Complex ◽

Monogalactosyl Diglyceride ◽

Prosthetic Groups ◽

Β Carotene

Plant photosystem I (PSI) is one of the most intricate membrane complexes in nature. It comprises two complexes, a reaction center and light-harvesting complex (LHC), which together form the PSI–LHC supercomplex. The crystal structure of plant PSI was solved with two distinct crystal forms. The first, crystallized at pH 6.5, exhibited P21 symmetry; the second, crystallized at pH 8.5, exhibited P212121 symmetry. The surfaces involved in binding plastocyanin and ferredoxin are identical in both forms. The crystal structure at 2.6 Å resolution revealed 16 subunits, 45 transmembrane helices, and 232 prosthetic groups, including 143 chlorophyll a, 13 chlorophyll b, 27 β-carotene, 7 lutein, 2 xanthophyll, 1 zeaxanthin, 20 monogalactosyl diglyceride, 7 phosphatidyl diglyceride, 5 digalactosyl diglyceride, 2 calcium ions, 2 phylloquinone, and 3 iron sulfur clusters. The model reveals detailed interactions, providing mechanisms for excitation energy transfer and its modulation in one of nature's most efficient photochemical machine.

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Effect of pressure on the crystal structure of L-serine-I and the crystal structure of L-serine-II at 5.4 GPa

Acta Crystallographica Section B Structural Science ◽

10.1107/s0108768104031787 ◽

2005 ◽

Vol 61 (1) ◽

pp. 58-68 ◽

Cited By ~ 79

Author(s):

Stephen A. Moggach ◽

David R. Allan ◽

Carole A. Morrison ◽

Simon Parsons ◽

Lindsay Sawyer

Keyword(s):

Crystal Structure ◽

Phase Transition ◽

Hydrogen Bonds ◽

Single Crystal ◽

Ambient Pressure ◽

Crystal Form ◽

Hydroxyl Groups ◽

Orthorhombic Space Group ◽

Crystal Forms ◽

Hydrogen Bonded

The crystal structure of L-serine has been determined at room temperature at pressures between 0.3 and 4.8 GPa. The structure of this phase (hereafter termed L-serine-I), which consists of the molecules in their zwitterionic tautomer, is orthorhombic, space group P212121. The least compressible cell dimension (c), corresponds to chains of head-to-tail NH...carboxylate hydrogen bonds. The most compressible direction is along b, and the pressure-induced distortion in this direction takes the form of closing up voids in the middle of R-type hydrogen-bonded ring motifs. This occurs by a change in the geometry of hydrogen-bonded chains connecting the hydroxyl groups of the —CH2OH side chains. These hydrogen bonds are the longest conventional hydrogen bonds in the system at ambient pressure, having an O...O separation of 2.918 (4) Å and an O...O...O angle of 148.5 (2)°; at 4.8 GPa these parameters are 2.781 (11) and 158.5 (7)°. Elsewhere in the structure one NH...O interaction reaches an N...O separation of 2.691 (13) Å at 4.8 GPa. This is amongst the shortest of this type of interaction to have been observed in an amino acid crystal structure. Above 4.8 GPa the structure undergoes a single-crystal-to-single-crystal phase transition to a hitherto uncharacterized polymorph, which we designate L-serine-II. The OH...OH hydrogen-bonded chains of L-serine-I are replaced in L-serine-II by shorter OH...carboxyl interactions, which have an O...O separation of 2.62 (2) Å. This phase transition occurs via a change from a gauche to an anti conformation of the OH group, and a change in the NCαCO torsion angle from −178.1 (2)° at 4.8 GPa to −156.3 (10)° at 5.4 GPa. Thus, the same topology appears in both crystal forms, which explains why it occurs from one single-crystal form to another. The transition to L-serine-II is also characterized by the closing-up of voids which occur in the centres of other R-type motifs elsewhere in the structure. There is a marked increase in CH...O hydrogen bonding in both phases relative to L-serine-I at ambient pressure.

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