Invariant amino acids essential for decoding function of polypeptide release factor eRF1

In eukaryotic ribosome, the N domain of polypeptide release factor eRF1 is involved in decoding stop signals in mRNAs. However, structure of the decoding site remains obscure. Here, we specifically altered the stop codon recognition pattern of human eRF1 by point mutagenesis of the invariant Glu55 and Tyr125 residues in the N domain. The 3D structure of generated eRF1 mutants was not destabilized as demonstrated by calorimetric measurements and calculated free energy perturbations. In mutants, the UAG response was most profoundly and selectively affected. Surprisingly, Glu55Arg mutant completely retained its release activity. Substitution of the aromatic ring in position 125 reduced response toward all stop codons. This result demonstrates the critical importance of Tyr125 for maintenance of the intact structure of the eRF1 decoding site. The results also suggest that Tyr125 is implicated in recognition of the 3d stop codon position and probably forms an H-bond with Glu55. The data point to a pivotal role played by the YxCxxxF motif (positions 125–131) in purine discrimination of the stop codons. We speculate that eRF1 decoding site is formed by a 3D network of amino acids side chains

Role of orexin peptide system in emotional overeating induced by brain reward stimulation in fed rats

The orexin A receptors are preferably involved in emotional eating compared with orexin B (OX2R TCS-OX2-29) and D2 dopamine receptors. Because emotional eating is significantly related to clinical eating disorders, like bulimia and binge eating disorder, it seems promising to use drugs of the orexin system to treat and prevent the issu

Новые комбинации и названия сосудистых растений Азиатской России.

In this paper, we present nomenclatural novelties required in the course of the preparation of the second, revised version of the checklist of vascular plants of Asian Russia. The first version was published in 2012 (Baikov 2012). At the family level, we accepted the modern classification systems (APG IV for flowering plants, PPG I for lycophytes and ferns, and GPG for gymnosperms). At the genus level, we follow the generic concepts applied for particular taxonomic groups according to the Catalogue of Life (COL; https://www.catalogueoflife.org/), version COL23.5. At the species level, we consistently apply the monotypic species concept (also known in Russia as Komarov’s concept). In total, this paper presents one new nothogenus name (× Sibirotrisetokoeleria Chepinoga nom. nov., Poaceae) and 156 new names in the rank of species, in 28 families: Amaranthaceae Juss. (1 name), Amaryllidaceae J. St.-Hil. (1), Apiaceae Lindl. (2), Asteraceae Bercht. & J.Presl (12), Boraginaceae Juss. (4), Caryophyllaceae Juss. (11), Crassulaceae J. St.-Hill. (3), Cyperaceae Juss. (8), Ericaceae Juss. (2), Fabaceae Lindl. (16), Gentianaceae Juss. (1), Geraniaceae Juss. (1), Juncaceae Juss. (1), Lamiaceae Martinov (1), Menyanthaceae Dumort. (1), Orchidaceae Juss. (1), Orobanchaceae Vent. (1), Papaveraceae Juss. (4), Plantaginaceae Juss. (1), Poaceae Barnhart (49), Polygonaceae Juss. (4), Primulaceae Batsch. ex Borkh. (6), Ranunculaceae Juss. (4), Rosaceae Juss. (5), Salicaceae Mirb. (2), Saxifragaceae Juss. (11), Vitaceae Juss. (1), Zygophyllaceae R. Br. (2 names)

Two-loop QED radiative corrections to the decay pi0 -> e+ e- : The virtual corrections and soft-photon bremsstrahlung

This paper is devoted to the two-loop QED radiative corrections to the decay pi0 -> e+ e-. We compute the virtual corrections without using any approximation and we take into account all the relevant graphs with the inclusion of those omitted in the previous approximative calculations. The bremsstrahlung is then treated within the soft photon approximation. We concentrate on the technical aspects of the calculation and discuss in detail the UV renormalization and the treatment of IR divergences within the dimensional regularization. As a result we obtain the O(alpha^3 p^2) contribution in closed analytic form. We compare the exact two-loop results with existing approximative calculations of QED corrections and find significant disagreement in the kinematical region relevant for the KTeV experiment.Comment: 48 pages plus 4 appendices (72 pages total), 26 figures; v3: new chapter 9 with phenomenological discussion added, references added, minor typos corrected; coincides with the journal versio

Morphogenesis of the T4 tail and tail fibers

Remarkable progress has been made during the past ten years in elucidating the structure of the bacteriophage T4 tail by a combination of three-dimensional image reconstruction from electron micrographs and X-ray crystallography of the components. Partial and complete structures of nine out of twenty tail structural proteins have been determined by X-ray crystallography and have been fitted into the 3D-reconstituted structure of the "extended" tail. The 3D structure of the "contracted" tail was also determined and interpreted in terms of component proteins. Given the pseudo-atomic tail structures both before and after contraction, it is now possible to understand the gross conformational change of the baseplate in terms of the change in the relative positions of the subunit proteins. These studies have explained how the conformational change of the baseplate and contraction of the tail are related to the tail's host cell recognition and membrane penetration function. On the other hand, the baseplate assembly process has been recently reexamined in detail in a precise system involving recombinant proteins (unlike the earlier studies with phage mutants). These experiments showed that the sequential association of the subunits of the baseplate wedge is based on the induced-fit upon association of each subunit. It was also found that, upon association of gp53 (gene product 53), the penultimate subunit of the wedge, six of the wedge intermediates spontaneously associate to form a baseplate-like structure in the absence of the central hub. Structure determination of the rest of the subunits and intermediate complexes and the assembly of the hub still require further study

Platanthera whangshanensis (S.S. Chien) Efimov, a Forgotten Orchid of Chinese Flora

Platanthera whangshanensis, a forgotten species of the Chinese flora, is described and illustrated. Originally it was described as a member of genus Perularia, and a corresponding new combination is here proposed. In the «Flora of China» this taxon was treated under the name Platanthera tipuloides, which is in turn a species that is absent from the flora of subtropical China. The localities of true Platanthera tipuloides may be found only in the north-west of the country. A doubtful record of Platanthera tipuloides from Liaoning Province is discussed

Finnish Industrial Area Market Research. Case Company: Nordic Access

This research-oriented bachelor’s thesis focuses on a study and analysis of a Finnish in-dustrial area market. The market research of this specific sector was conducted for a case company called Nordic Access. In collaboration with the company, the key factors affecting the market, competitive field, and opportunities to expand on the market are were studied, and the results of the research can be considered and implemented by Nordic Access. The commissioning company specializes in industrial solutions and provides services such as rope access, building maintenance, and inspections. The key factor of the company’s operations is that most of the company’s projects are based on rope access technology. The market of methodology provider is developing at the time of writing this thesis, hence, the company can impact on its development as a part of the expansion. The theoretical framework of the thesis deals with methodologies and approaches useful for conducting market research. The theory presented in the thesis was used in practice at the further stages of research. The importance of a careful choice of approaches relies on the results, that the author of this thesis and the commissioning company are expecting from this research. Qualitative research methods were applied in the thesis, due to a specific market. More precisely, the company operates in the B2B sector, and every aspect, including customers, should be investigated by using qualitative methods. The data for this thesis was gathered through interviews with the company’s representatives, and from the information available on websites related to the studied market. The empirical part of the thesis presents the research process, beginning from the coun-try’s business environment overview and an analysis of the industry, narrowing down to an investigation related to the studied market, considering the competitive field and potential partnerships. The final parts of the thesis present the key findings gathered on every stage of a research process. With the help of data analyzed during the research, the author states the viability of a target market and proves the existence of potential opportunities for the expansion of a case company. Additionally, the author analyzed the strengths and weaknesses of a company and presented them with regard to a market situation. The key suggestions to Nordic Access are to continue actively participate in events related to the industrial solutions market, develop the sales department of a company, and provide a company with IRATA partnership and ISO 9001 certificate. Additionally, the author rec-ommends contacting companies presented in this thesis as a list of potential customers

An intriguing morphological variability of Platanthera s.l.

The morphology of 38 species of the genus Platanthera s.l. was investigated by means of light and electron microscopy. Particular attention was paid to the structure of gynostemium and pollinaria. The species investigated represent 10 major lineages of the genus, all being recognized as sections or segregate genera in various taxonomical treatments. Considerable morphological variability was confirmed for Platanthera s.l. The most notably variable structures are tuberoids (root-like, stoloniferous, spherical, etc.), lip (entire, lobed, fimbriate etc.), rostellar lateral lobes (flat, concave, bursicle-like), lateral stigma lobes (flat, protruding, etc.) and viscidia (orbicular, lanceolate, sub-linear, deeply concave, reduced). The morphology of several taxa confirms that they do not belong to Platanthera s.l., of them Platanthera camtschatica displays relation to Galearis s.l. and P. latilabris, P. clavigera and P. biermanniana – to subtribe Habenariinae. In many cases the morphology confirms the monophyly of the lineages within Platanthera s.l., as Tulotis, Limnorchis etc., although more thorough sampling is needed. Some of those groups correspond to the clades as defined by previously published molecular phylogenies (Hapeman and Inoue 1997, Bateman et al. 2009). The morphological polymorphism in Platanthera s.l. (especially gynostemium structure) seems to be higher than in many other large genera of the subtribe Orchidinae, as Dactylorhiza, Ophrys or Orchis, and led to recognition of several segregate genera within Platanthera s.l. However, lesser genetic polymorphism revealed by molecular markers gives evidence for morphological plasticity (in particular, in gynostemium structure) and rapid morphological evolution of this group

Revealing the decline and expansion of orchids of NW European Russia

A new approach to reveal the dynamics of taxa on incompletely investigated territories was developed. The decline/expansion rate of orchids in the North Western part of European Russia (Leningrad, Novgorod and Pskov Regions, an area approx. 195,000 km2) was estimated using this method. The method is based on comparison of numbers of grid cells where a certain species was recorded in various time intervals using specially designed software. More than 9000 records were used, however the territory remained insufficiently and unevenly studied both spatially and over time. The study revealed a statistically significant (p < 0.01) decrease for Coeloglossum viride, Corallorhiza trifida, Cypripedium calceolus, Gymnadenia conopsea, Herminium monorchis, Malaxis monophyllos, Neotinea ustulata and Orchis militaris and a significant increase for Dactylorhiza baltica, D. fuchsii and Platanthera chlorantha. In several taxa, the trend was changed over the time. Of them, Gymnadenia conopsea displayed significant decline only since the middle of XX century, and Orchis militaris and Epipactis atrorubens decreased significantly only in the end of XIX and the beginning of XX century. The reasons for these patterns of dynamics were discussed. Parallels between the dynamics of orchids and land use in different periods of time in Russia are provided