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Toll-like receptors (TLRs) play an important role in the innate immune response. While a lot is known about the structures of their extracellular parts, many questions are still left unanswered, when the structural basis of TLR activation is analyzed for the TLR intracellular domains. Here we report the structure and dynamics of TLR1 toll-interleukin like (TIR) cytoplasmic domain in crystal and in solution. We found that the TLR1-TIR domain is capable of specific binding of Zn with nanomolar affinity. Interactions with Zn are mediated by cysteine residues 667 and 686 and C667 is essential for the Zn binding. Potential structures of the TLR1-TIR/Zn complex were predicted in silico. Using the functional assays for the heterodimeric TLR1/2 receptor, we found that both Zn addition and Zn depletion affect the activity of TLR1, and C667A mutation disrupts the receptor activity. Analysis of C667 position in the TLR1 structure and possible effects of C667A mutation, suggests that zinc-binding ability of TLR1-TIR domain is critical for the receptor activation., Lushpa et al report the structure and dynamics of the TLR1 toll-interleukin like (TIR) cytoplasmic domain in both crystal and solution. They demonstrate that the TLR1 TIR domain is capable of specific binding of Zn with nanomolar affinity, which appears to be critical for receptor activation, and provide potential structures TLR1-TIR/Zn complex based on in silico data.

The article highlights the problem of practical implementation of such a security measure that can be applied to participants in criminal proceedings, such as ensuring the confidentiality of personal information. It is analyzed the views diversity of investigators, prosecutors, judges and lawyers on the algorithm of application of ensuring the personal data confidentiality, on the issue of storage of resolutions (decisions) on the application of this security measure in criminal proceedings. The practice of conducting procedural actions in court with persons whose personal data have been changed is studied separately. The peculiarities of interrogation, identification with protected participants of criminal proceedings in the mode of videoconference and in a closed court session are studied. Previous attempts to solve this problem by developing a Model Instruction on conducting court proceedings with witnesses, victims and other participants in criminal proceedings, in respect of whom security measures have been taken, are considered. According to the analysis results of the domestic legislation on security of participants in criminal proceedings and identification of gaps, after conducting a survey of current investigators, prosecutors, judges and lawyers, the generalization of modern practice of criminal proceedings with the participation of protected persons is made. The purpose of this research is to formulate proposals for a unified and mandatory for all participants in criminal proceedings procedure for working with persons whose personal data are changed for security purposes at all stages of criminal proceedings. The expediency of enshrining at the bylaw level in a separate normative legal act an algorithm for carrying out procedural actions in court with participants in criminal proceedings, which would meet the requirements of current legislation, including the provisions of the Data Summary constituting a state secret, is substantiated.

The behavior of the peptide substrates GlyArgArgGly and GlyLysArgGly, which contain arginine or lysine at the Р2 position, in the active site of oligopeptidase В from the gamma-proteobacterium Serratia proteamaculans was studied by molecular dynamics simulations. The nature of the residue at the Р2 position was shown not only to influence the position of this residue and its contacts with the amino-acid environment in the substrate-binding pocket but also to affect the conformational dynamics of the entire peptide. Only the residue at the Р1 position forms persistent contacts with the S1-substrate-binding site of the enzyme, whereas contacts of the residue at the Р2 position may vary depending on its nature. Molecular dynamics simulations are shown to complement and improve the knowledge extracted from X-ray diffraction studies that enable the determination of the three-dimensional structures of molecules in one of numerous alternative conformations.

DNA-Binding HU proteins are critical to the maintenance of the nucleoid structure and are promising pharmacological targets for the design of new antibiotics. The virtual screening for low-molecular-weight compounds capable of specifically interacting with the dimerization signals of two mycoplasma HU proteins was performed. The stability of target protein–ligand complexes was evaluated by molecular dynamics simulation. An analysis of the amino-acid environment of the ligands shows that inhibitors targeting the conserved amino-acid sequence, the so-called dimerization signal, which is involved in the formation of HU dimers and the maintenance of their stability and is located in an interdimer beta-sheet, have the second binding site in the alpha-helical domain. The binding determinants of inhibitors at the dimer interfaces of the proteins are identical and are independent of the amino-acid sequence. Consequently, HU proteins have two sites for the formation of the dimer interface, which should be taken into account in the design of inhibitors of dimerization.

Mediating transcription The Mediator complex is recruited by transcription factors to all protein-coding genes in eukaryotes and helps to assemble the machinery necessary to transcribe the gene. Abdella et al. present the cryo–electron microscopy structure of the human Mediator-bound preinitiation complex (Med-PIC). The structure shows how Mediator positions the long, flexible C-terminal domain of RNA polymerase II to be phosphorylated by the kinase CDK7, a crucial step for further processing of the RNA into a mature RNA. Most sites where transcription factors bind to Mediator are flexibly tethered to the complex, allowing the large Med-PIC to assemble at any gene. Science , this issue p. 52

Feeding lactating sows with the probiotic supplements “Citexflor-1” and “Sgol-1-40” at 14.4–13.1 MJ of exchange energy released from digesting 1 kg of dry matter of feed mixtures included in the diet had a positive effect on productivity, nutrient digestibility and morphological and biochemical parameters of blood. The inclusion of adequate amounts of “Citexflor-1” enhanced milk production by sows in the second trial group compared to the control by 2.03 %, in the third by 6.6 % and in the fourth by 3.9 %, with the survival in piglets observed at 89–92 %. Supplementation of probiotic preparation “Sgol-1-40” was carried out, the sows showed to produce more milk by 5.8 % in the second trial group, 16.3 % in the third, and 20.7 % in the fourth group compared to the control. In the study of morphological and biochemical parameters of blood in sows in the first experiment, the erythrocyte number was greater in the third trial group by 6.2 %, and in the fourth by 4.7 %. In the second experiment, with probiotic supplementation of “Sgol-1-40” fed to sows, the number of red blood cells was 4.2; 18.1 and 32.1 % greater, respectively, along with hemoglobin level higher at 2.8; 15.3; 24.1 %, respectively.

Human cancers frequently display defects in Ag processing and presentation allowing for immune evasion, and they therefore constitute a significant challenge for T cell–based immunotherapy. We have previously demonstrated that the antigenicity of tumor-associated Ags can be significantly enhanced through unconventional residue modifications as a novel tool for MHC class I (MHC-I)–based immunotherapy approaches. We have also previously identified a novel category of cancer neo-epitopes, that is, T cell epitopes associated with impaired peptide processing (TEIPP), that are selectively presented by MHC-I on cells lacking the peptide transporter TAP. In this study, we demonstrate that substitution of the nonanchoring position 3 into a proline residue of the first identified TEIPP peptide, the murine Trh4, results in significantly enhanced recognition by antitumor CTLs toward the wild-type epitope. Although higher immunogenicity has in most cases been associated with increased MHC/peptide complex stability, our results demonstrate that the overall stability of H-2Db in complex with the highly immunogenic altered peptide ligand Trh4-p3P is significantly reduced compared with wild-type H-2Db/Trh4. Comparison of the crystal structures of the H-2Db/Trh4-p3P and H-2Db/Trh4 complexes revealed that the conformation of the nonconventional methionine anchor residue p5M is altered, deleting its capacity to form adequate sulfur–π interactions with H-2Db residues, thus reducing the overall longevity of the complex. Collectively, our results indicate that vaccination with Thr4-p3P significantly enhances T cell recognition of targets presenting the wild-type TEIPP epitope and that higher immunogenicity is not necessarily directly related to MHC/peptide complex stability, opening for the possibility to design novel peptide vaccines with reduced MHC/peptide complex stability.

DNA-Binding HU proteins are essential for the maintenance of genomic DNA supercoiling and compaction in prokaryotic cells and are promising pharmacological targets for the design of new antibacterial agents. The virtual screening for low-molecular-weight compounds capable of specifically interacting with the DNA-recognition loop of the HU protein from the mycoplasma Spiroplasma melliferum was performed. The ability of the initially selected ligands to form stable complexes with the protein target was assessed by molecular dynamics simulation. One compound, which forms an unstable complex, was eliminated by means of a combination of computational methods, resulting in a decrease in the number of compounds that will pass to the experimental test phase. This approach can be used to solve a wide range of problems related to the search for and validation of low-molecular-weight inhibitors specific for a particular protein target.

The rise of antibiotic resistance has necessitated the development of alternative strategies for the treatment of infectious diseases. Antimicrobial peptides (AMPs), components of the innate immune response in various organisms, are promising next-generation drugs against bacterial infections. The ability of the medicinal leech Hirudo medicinalis to store blood for months with little change has attracted interest regarding the identification of novel AMPs in this organism. In this study, we employed computational algorithms to the medicinal leech genome assembly to identify amino acid sequences encoding potential AMPs. Then, we synthesized twelve candidate AMPs identified by the algorithms, determined their secondary structures, measured minimal inhibitory concentrations against three bacterial species ( Escherichia coli , Bacillus subtilis , and Chlamydia thrachomatis ), and assayed cytotoxic and haemolytic activities. Eight of twelve candidate AMPs possessed antimicrobial activity, and only two of them, 3967 (FRIMRILRVLKL) and 536–1 (RWRLVCFLCRRKKV), exhibited inhibition of growth of all tested bacterial species at a minimal inhibitory concentration of 10 μmol. Thus, we evidence the utility of the developed computational algorithms for the identification of AMPs with low toxicity and haemolytic activity in the medicinal leech genome assembly.

The paper considers the experimentally confirmed data on marl efficiency in the zones with increased level of radionuclides in the soil (5–10 and 15–40 Ki/km2) in the last third of female pig pregnancy in the amount of 2.0 % of the diet dry matter. Feeding with local mineral supplement increases the reproductive functions of breeding pigs, in particular, the number of stillborn piglets decreased by 1.64–7.70 % and their safety to weaning increased by 4.8–11.9 %. The increase of redox and metabolic processes in the animal body of the experimental groups positively affected the milking capacity of the breeding stock increasing it by 6.8–21.9 % and the growth of piglets, which was confirmed by their larger body weight by 3.3 and 4.6 %. The sorption properties of marl allowed reducing the concentration of toxic lead in the body of breeding pigs (by 40.17 and 42.01 %) and cadmium (by 20.57 and 24.42 %), decreasing the transition of cesium-137 isotope to beestings milk by 1.34 and 1.28 times. In areas with high soil pollution with radiocesium in Bryansk region, the use of natural marl sorbent in breeding pigs’ diets activates their immunity, hematopoietic functions, accelerates assimilation of protein and mineral exchange.

The histone-like (HU) protein is one of the major nucleoid-associated proteins of the bacterial nucleoid, which shares high sequence and structural similarity with IHF but differs from the latter in DNA-specificity. Here, we perform an analysis of structural-dynamic properties of HU protein from Spiroplasma melliferum and compare its behavior in solution to that of another mycoplasmal HU from Mycoplasma gallisepticum. The high-resolution heteronuclear NMR spectroscopy was coupled with molecular-dynamics study and comparative analysis of thermal denaturation of both mycoplasmal HU proteins. We suggest that stacking interactions in two aromatic clusters in the HUSpm dimeric interface determine not only high thermal stability of the protein, but also its structural plasticity experimentally observed as slow conformational exchange. One of these two centers of stacking interactions is highly conserved among the known HU and IHF proteins. Second aromatic core described recently in IHFs and IHF-like proteins is considered as a discriminating feature of IHFs. We performed an electromobility shift assay to confirm high affinities of HUSpm to both normal and distorted dsDNA, which are the characteristics of HU protein. MD simulations of HUSpm with alanine mutations of the residues forming the non-conserved aromatic cluster demonstrate its role in dimer stabilization, as both partial and complete distortion of the cluster enhances local flexibility of HUSpm.

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Byzance, un monde à part, retranche dans la splendeur de ses palais et de ses églises, peu accueillant envers l'étranger, menant une économie de subsistance ! Rien de plus faux que ces cliches persistants, rien de plus éloigné d'une réalité historique que les recherches récentes mettent en pleine lumière. Après les Russes et les musulmans, voici que les Occidentaux envahissent Constantinople, « la reine des villes », mais aussi toutes les provinces de l'Empire : la Thessalie, la Macédoine, le Péloponnèse, Chypre, les iles égéennes, la mer Noire constituent les domaines d'expansion des soldats au service de l'empereur, des ambassadeurs et surtout des marchands. Leur sécurité et leurs activités sont garanties par des traites internationaux, prépares par des échanges diplomatiques. Toute une chancellerie est au travail, avec un langage propre, des pratiques éprouvées, des interprètes, des traducteurs et des envoyés indispensables. Des usages diplomatiques se mettent en place. La création artistique n'échappe pas aux contacts entre les cultures ; vêtements d'apparat, vaisselle de table, architecture et sculpture donnent lieu a des confrontations fécondes entre Orient et Occident. L'Empire est largement ouvert a l'Autre ; les essais ici rassembles le démontrent sans équivoque.