4-Amino­pyridinium 4-carb­oxy­butano­ate

The asymmetric unit of the title salt, C5H7N2 +·C5H7O4 −, contains two 4-amino­pyridinium cations and two 4-carb­oxy­butano­ate anions. Each 4-amino­pyridinium cation is planar, with a maximum deviation of 0.005 (2) Å. Both 4-carb­oxy­butano­ate anions adopt an extended conformation. In the crystal structure, the cations and anions are linked via N—H⋯O, O—H⋯O and C—H⋯O hydrogen bonds, forming a two-dimensional network parallel to the bc plane

2-Amino-5-chloro­pyrimidin-1-ium hydrogen maleate

In the title salt, C4H5ClN3 +·C4H3O4 −, the 2-amino-5-chloro­pyrimidinium cation is protonated at one of its pyrimidine N atoms. In the roughly planar (r.m.s. deviation = 0.026 Å) hydrogen malate anion, an intra­molecular O—H⋯O hydrogen bond generates an S(7) ring. In the crystal, the protonated N atom and the 2-amino group of the cation are hydrogen bonded to the carboxyl­ate O atoms of the anion via a pair of N—H⋯O hydrogen bonds, forming an R 2 2(8) ring motif. The ion pairs are connected via further N—H⋯O hydrogen bonds and a short C—H⋯O inter­action, forming layers lying parallel to the bc plane

4-Amino­pyridinium 2-hy­droxy­benzoate

In the salicylate anion of the title salt, C5H7N2 +·C7H5O3 −, an intra­molecular O—H⋯O hydrogen bond generating an S(6) ring motif is observed. In the crystal structure, the cations and anions are linked into a two-dimensional network parallel to the ab plane by N—H⋯O and C—H⋯O hydrogen bonds. The network contains R 2 2(7) and R 1 2(4) ring motifs. Weak π–π inter­actions between the benzene and pyridinium rings [centroid–centroid distance = 3.688 (1) Å] are also observed

Structure of the C-terminal domain of the multifunctional ICP27 protein from herpes simplex virus 1

Herpesviruses are nuclear-replicating viruses that have successfully evolved to evade the immune system of humans, establishing lifelong infections. ICP27 from herpes simplex virus is a multifunctional regulatory protein that is functionally conserved in all known human herpesviruses. It has the potential to interact with an array of cellular proteins, as well as intronless viral RNAs. ICP27 plays an essential role in viral transcription, nuclear export of intronless RNAs, translation of viral transcripts, and virion host shutoff function. It has also been implicated in several signaling pathways and the prevention of apoptosis. Although much is known about its central role in viral replication and infection, very little is known about the structure and mechanistic properties of ICP27 and its homologs. We present the first crystal structure of ICP27 C-terminal domain at a resolution of 2.0 Å. The structure reveals the C-terminal half of ICP27 to have a novel fold consisting of -helices and long loops, along with a unique CHCC-type of zinc-binding motif. The two termini of this domain extend from the central core and hint to possibilities of making interactions. ICP27 essential domain is capable of forming self-dimers as seen in the structure, which is confirmed by analytical ultracentrifugation study. Preliminary in vitro phosphorylation assays reveal that this domain may be regulated by cellular kinases.Published versio

The crystal structure of the DNA-binding domain of vIRF-1 from the oncogenic KSHV reveals a conserved fold for DNA binding and reinforces its role as a transcription factor

Kaposi’s sarcoma-associated herpesvirus encodes four viral homologues to cellular interferon regulatory factors (IRFs), where the most studied is vIRF-1. Even though vIRF-1 shows sequence homology to the N-terminal DNA-binding domain (DBD) of human IRFs, a specific role for this domain in vIRF-1’s function has remained uncertain. To provide insights into the function of the vIRF-1 DBD, we have determined the crystal structure of it in complex with DNA and in its apo-form. Using a thermal stability shift assay (TSSA), we show that the vIRF-1 DBD binds DNA, whereas full-length vIRF-1 does not, suggesting a cis-acting regulatory mechanism in similarity to human IRFs. The complex structure of vIRF-1 DBD reveals interactions with the DNA backbone and the positioning of two arginines for specific recognition in the major grove. A superimposition with human IRF-3 reveals a similar positioning of the two specificity-determining arginines, and additional TSSAs indicate binding of vIRF-1 to an IRF-3 operator consensus sequence. The results from this study, therefore, provide support that vIRF-1 has evolved to bind DNA and plays a role in DNA binding in the context of transcriptional regulation and might act on some of the many operator sequences controlled by human IRF-3.Published versio

Structure of the C-Terminal Domain of the Multifunctional ICP27 Protein from Herpes Simplex Virus 1

Herpesviruses are nuclear-replicating viruses that have successfully evolved to evade the immune system of humans, establishing lifelong infections. ICP27 from herpes simplex virus is a multifunctional regulatory protein that is functionally conserved in all known human herpesviruses. It has the potential to interact with an array of cellular proteins, as well as intronless viral RNAs. ICP27 plays an essential role in viral transcription, nuclear export of intronless RNAs, translation of viral transcripts, and virion host shutoff function. It has also been implicated in several signaling pathways and the prevention of apoptosis. Although much is known about its central role in viral replication and infection, very little is known about the structure and mechanistic properties of ICP27 and its homologs. We present the first crystal structure of ICP27 C-terminal domain at a resolution of 2.0 Å. The structure reveals the C-terminal half of ICP27 to have a novel fold consisting of α-helices and long loops, along with a unique CHCC-type of zinc-binding motif. The two termini of this domain extend from the central core and hint to possibilities of making interactions. ICP27 essential domain is capable of forming self-dimers as seen in the structure, which is confirmed by analytical ultracentrifugation study. Preliminary in vitro phosphorylation assays reveal that this domain may be regulated by cellular kinases. IMPORTANCE ICP27 is a key regulatory protein of the herpes simplex virus and has functional homologs in all known human herpesviruses. Understanding the structure of this protein is a step ahead in deciphering the mechanism by which the virus thrives. In this study, we present the first structure of the C-terminal domain of ICP27 and describe its novel features. We critically analyze the structure and compare our results to the information available form earlier studies. This structure can act as a guide in future experimental designs and can add to a better understanding of mechanism of ICP27, as well as that of its homologs

Purification, crystallization and preliminary X-ray diffraction analysis of the HMG domain of Sox17 in complex with DNA

Crystals of the Sox17 HMG domain bound to LAMA1 enhancer DNA-element crystals that diffracted to 2.75 Å resolution were obtained

Crystal structure, in silico molecular docking, DFT analysis and ADMET studies of N-(2-methoxy-benzyl)-acetamide

In this work, N-(2-methoxy-benzyl)-acetamide (2MBA) was synthesized from an amide derivative and it was characterized by FT-IR and NMR spectroscopy techniques. The crystal structure of 2MBA was also validated via single-crystal X-ray diffraction analysis. Crystal data for C10H13NO2 for 2MBA: Monoclinic, space group P21/n (no. 14), a = 9.1264(6) Å, b = 9.3375(7) Å, c = 11.9385(8) Å, β = 95.745(5)°, V = 1012.26(12) Å3, Z = 4, μ(MoKα) = 0.082 mm-1, Dcalc = 1.176 g/cm3, 5632 reflections measured (5.368° ≤ 2Θ ≤ 51.992°), 1990 unique (Rint = 0.0377, Rsigma = 0.0314) which were used in all calculations. The final R1 was 0.0583 (I > 2σ(I)) and wR2 was 0.1444 (all data).  The intermolecular interactions in 2MBA were theoretically examined by Hirshfeld surface analysis and 2D fingerprint plots. Moreover, the HOMO and LUMO energy gaps of 2MBA was calculated by DFT calculation with the B3LYP/6-311G++(d,p) method. The electron-withdrawing and donating sites of the 2MBA were confirmed via molecular electrostatic potential surface analysis. The present study discusses the title compound not only highlighted the crystallographic data but also revealed good molecular interactions together with an anticancer drug target, which is a targeting PARP protein, which was an important drug target in the treatment of breast cancer