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research papers
Structural and mutational studies of the active-site residues and also of those forming salt bridges between subdomains and active-site residues of the adenylation domain were carried out in M. tuberculosis NAD+-dependent DNA ligase A. The results suggest that specific salt bridges mediated by Glu22, Glu26 and Glu87 are important for the correct subdomain geometry and that their disruption critically impacts on the adenylation activity. At the same time, even conservative mutations of His236 and Lys123 in the active site lead to severe activity loss.
organic compounds
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In the title compound, 2C14H8N4O6·CH2Cl2, the dichloromethane solvent molecule resides on a crystallographic twofold axis. The mean plane of the phthalisoimide ring is oriented at a dihedral angle of 32.93 (12)° with respect to the nitro-substituted benzene ring. An intramolecular N—H
O hydrogen bond occurs. The crystal packing features a short ClO halogen-bond interaction [3.093 (3) Å].
O hydrogen bond occurs. The crystal packing features a short ClO halogen-bond interaction [3.093 (3) Å].
crystallization communications
A 17 kDa capsid protease domain from Aura virus was purified, crystallized together with its complex with dioxane and characterized by the X-ray diffraction method.
research papers
The crystal structure of pyroglutamate (pG) bound PCP I enzyme reveals the mechanism of its pG specificity. The residues of a conserved active-site loop interact with pG via phenylalanine stacking interactions and hydrogen bonds.
research papersThe crystal structure of pyroglutamate (pG) bound PCP I enzyme reveals the mechanism of its pG specificity. The residues of a conserved active-site loop interact with pG via phenylalanine stacking interactions and hydrogen bonds.
research papers
The replacement of the OH group at the C3′ position of a furanose ring by fluorine changes the N-type furanose ring puckering to S-type in the crystalline state.
organic compoundsOpen access
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The asymmetric unit of the title compound, C26H12ClNO6, consists of two independent molecules. The central pyran rings and both the 1-benzopyran ring systems are nearly planar in both molecules [r.m.s. deviations of pyan rings = 0.0264 (1) and 0.0326 (1) Å for molecules A and B, respectively; r.m.s. deviations of benzopyran rings = 0.0439 (1) and 0.0105 (1) for molecule A, 0.0146 (1) and 0.0262 (1) Å for molecule B]. In the crystal, the molecules are linked by C—HO, N—HO and C—Hπ interactions.
O, N—HO and C—Hπ interactions.organic compoundsOpen access
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In the title compound, C21H13ClO, the central anthracene system is distorted towards a boat conformation and the outer rings are not coplanar with the central ring [dihedral angles = 7.79 (1) and 11.90 (1)°]. The crystal structure features inversion dimers with graph-set motif R22(18) formed by C—HO interactions.
O interactions.organic compoundsOpen access
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In the title compound, C40H34N2O2, the central piperidine ring adopts a half-chair conformation and the fused pyrrolidine rings adopt twisted envelope (with the C atom bearing the methylphenyl ring as the flap atom) and envelope (with the C atom bound to the N atom, common to the pyridinone and pyrrolidine rings being the flap atom) conformations. The molecular structure features weak intramolecular N—HO and C—HO interactions. In the crystal, O—HO hydrogen bonds generate a C(7) chain along the b-axis direction. C—HO interactions also occur.
O and C—HO interactions. In the crystal, O—HO hydrogen bonds generate a C(7) chain along the b-axis direction. C—HO interactions also occur.organic compoundsOpen access
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In the title compound, C26H12FNO6, the central pyran ring and both benzopyran systems are nonplanar, having total puckering amplitudes of 0.139 (2), 0.050 (1) and 0.112 (2) Å, respectively. The central pyran ring adopts a boat conformation. The crystal structure is stabilized by C—HO, N—HO, N—HF and C—Hπ interactions.
O, N—HO, N—HF and C—Hπ interactions.organic compoundsOpen access
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In the title compound, C27H15NO6·0.5CHCl3, the central pyran ring and both the benzopyran systems are planar, with the dihedral angle between the outer rings being 3.24 (6)°. The indolin-2-one system is in a perpendicular configuration with respect to the pyran ring [dihedral angle = 87.58 (2)°]. Supramolecular layers in the ac plane are formed in the crystal structure whereby inversion-related molecules are connected by N—HO hydrogen bonds. These are further linked by C—HO interactions, forming a supramolecular layer in the ac plane. Disordered CHCl3 solvent in the structure was modelled with the SQUEEZE routine in PLATON [Spek (2009). Acta Cryst. D65, 148–155].
O hydrogen bonds. These are further linked by C—HO interactions, forming a supramolecular layer in the ac plane. Disordered CHCl3 solvent in the structure was modelled with the SQUEEZE routine in PLATON [Spek (2009). Acta Cryst. D65, 148–155].organic compoundsOpen access
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The piperidine ring in the title compound, C24H25NO3, adopts an envelope conformation with the N atom being the flap atom, and each C=C double bond exhibits an E conformation. In the crystal, C—HO hydrogen bonds link the molecules, forming supramolecular layers that stack along the a axis.
O hydrogen bonds link the molecules, forming supramolecular layers that stack along the a axis.organic compoundsOpen access
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In the title compound, C15H11BrO3, the dihedral angle between the benzene rings is 72.59 (6)°. In the crystal, pairs of C—Hπ contacts form inversion dimers. Additional C—HO hydrogen bonds generate R21(6) ring motifs and stack these dimers along the b axis. Short intermolecular BrO contacts of 3.254 (3) Å are also observed and link the stacks into a three-dimensional network.
π contacts form inversion dimers. Additional C—HO hydrogen bonds generate R21(6) ring motifs and stack these dimers along the b axis. Short intermolecular BrO contacts of 3.254 (3) Å are also observed and link the stacks into a three-dimensional network.
data reports
In the title molecular salt, one of the cations is doubly protonated and one is singly protonated with charge balance achieved by three sulfonate anions. The crystal structure features interionic N—HO and C—HO hydrogen bonds.
O and C—HO hydrogen bonds.research papers (organic compounds)
data reports
The title salt consists of a 1H-benzo[d]imidazol-3-ium cation and a (Z)-carboxyprop-2-enoate anion. The crystal structure features N—HO and C—HO hydrogen bonds.
O and C—HO hydrogen bonds.data reports
In the title molecular salt, the benzimidazole ring of the cation is protonated at its N atom and the L-aspartate zwitterion anion is deprotonated at an O atom. In the crystal, the anions are linked via three N—HO hydrogen bonds involving the NH3+ group, forming layers parallel to the ab plane. The benzimidazolium cations are linked to these layers by N—HO hydrogen bonds. The layers are linked via C—HO hydrogen bonds, forming a three-dimensional structure. There are also C—Hπ interactions present involving inversion-related benzimidazolium cations.
O hydrogen bonds involving the NH3+ group, forming layers parallel to the ab plane. The benzimidazolium cations are linked to these layers by N—HO hydrogen bonds. The layers are linked via C—HO hydrogen bonds, forming a three-dimensional structure. There are also C—Hπ interactions present involving inversion-related benzimidazolium cations.data reportsOpen access
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In the anion of the title molecular salt, C7H7N2+·C7H5O3− (systematic name: 1H-benzimidazol-3-ium 2-hydroxybenzoate), there is an intramolecular O—HO hydrogen bond that generates an S(6) ring motif. The CO2 group makes a dihedral angle of 5.33 (15)° with its attached ring. In the crystal, the dihedral angle between the benzimidazolium ring and the anion benzene ring is 75.88 (5)°. Two cations bridge two anions via two pairs of N—HO hydrogen bonds, enclosing an R44(16) ring motif, forming a four-membered centrosymmetric arrangement. These units are linked via C—HO hydrogen bonds, forming chains propagating along the b-axis direction. The chains are linked by C—Hπ and π–π interactions [inter-centroid distances = 3.4156 (7) and 3.8196 (8) Å], forming a three-dimensional structure.
O hydrogen bond that generates an S(6) ring motif. The CO2 group makes a dihedral angle of 5.33 (15)° with its attached ring. In the crystal, the dihedral angle between the benzimidazolium ring and the anion benzene ring is 75.88 (5)°. Two cations bridge two anions via two pairs of N—HO hydrogen bonds, enclosing an R44(16) ring motif, forming a four-membered centrosymmetric arrangement. These units are linked via C—HO hydrogen bonds, forming chains propagating along the b-axis direction. The chains are linked by C—Hπ and π–π interactions [inter-centroid distances = 3.4156 (7) and 3.8196 (8) Å], forming a three-dimensional structure.
abstracts
data reports
In the crystal of the title compound, C17H19NO3S2, inversion dimers linked by pairs of weak C—HO hydrogen bonds generate 
(16) loops.
O hydrogen bonds generate 
(16) loops.
