Crystal Structure of Fad35R from Mycobacterium tuberculosis H37Rv in the Apo-State

Fad35R from Mycobacterium tuberculosis binds to the promoter site of Fad35 operon and its DNA binding activities are reduced in the presence of tetracycline and palmitoyl-CoA. We resolved the crystal structure of Fad35R using single-wavelength anomalous diffraction method (SAD). Fad35R comprises canonical DNA binding domain (DBD) and ligand binding domain (LBD), but displays several distinct structural features. Two recognition helices of two monomers in the homodimer are separated by ~ 48 Å and two core triangle-shaped ligand binding cavities are well exposed to solvent. Structural comparison with DesT and QacR structures suggests that ligand binding-induced movement of α7, which adopts a straight conformation in the Fad35R, may be crucial to switch the conformational states between repressive and derepressive forms. Two DBDs are packed asymmetrically, creating an alternative dimer interface which coincides with the possible tetramer interface that connects the two canonical dimers. Quaternary state of alternative dimer mimics a closed-state structure in which two recognition helices are distanced at ~ 35 Å and ligand binding pockets are inaccessible. Results of biophysical studies indicate that Fad35R has the propensity to oligomerize in solution in the presence of tetracycline. We present the first structure of a FadR homologue from mycobacterium and the structure reveals DNA and ligand binding features of Fad35R and also provides a view on alternative quaternary states that mimic open and closed forms of the regulator.     

An early Miocene deep‐water decapod crustacean faunule from the Vienna Basin (Western Carpathians,Slovakia)

Abstract: A decapod crustacean faunule from the lower Miocene (upper Burdigalian, ‘Karpatian’) of the Slovakian part of the Vienna Basin comprise five new species: Callianopsis marianae (Ctenochelidae), Crosniera schweitzerae (Thomassiniidae), Agononida cerovensis and Munidopsis lieskovensis (both Galatheidae) plus Mursia harnicari (Calappidae). The new species of Callianopsis is the first undoubted member of the genus to be recorded from Europe; it is based on sexually dimorphic major and minor chelae as well as on portions of carapace and abdomen. Crosniera schweitzerae sp. nov. and Agononida cerovensis sp. nov. constitute the first fossil members of these genera. Additional material of an enigmatic crab, Styrioplax exiguus, and a re‐examination of the type material, confirms assignment of that genus to the subfamily Rhizopinae (family Pilumnidae). Palaeoecological data suggest that deposition of the levels (Lak?árska Nová Ves Formation) from which these taxa were collected took place under generally low‐energy, deep‐water conditions that were conducive to the preservation of delicate structures. Palaeobiogeographical affinities of the described taxa suggest a trans‐Atlantic migration during the early Miocene.     

Y-chromosome variation in Altaian Kazakhs reveals a common paternal gene pool for Kazakhs and the influence of Mongolian expansions

Kazakh populations have traditionally lived as nomadic pastoralists that seasonally migrate across the steppe and surrounding mountain ranges in Kazakhstan and southern Siberia. To clarify their population history from a paternal perspective, we analyzed the non-recombining portion of the Y-chromosome from Kazakh populations living in southern Altai Republic, Russia, using a high-resolution analysis of 60 biallelic markers and 17 STRs. We noted distinct differences in the patterns of genetic variation between maternal and paternal genetic systems in the Altaian Kazakhs. While they possess a variety of East and West Eurasian mtDNA haplogroups, only three East Eurasian paternal haplogroups appear at significant frequencies (C3*, C3c and O3a3c*). In addition, the Y-STR data revealed low genetic diversity within these lineages. Analysis of the combined biallelic and STR data also demonstrated genetic differences among Kazakh populations from across Central Asia. The observed differences between Altaian Kazakhs and indigenous Kazakhs were not the result of admixture between Altaian Kazakhs and indigenous Altaians. Overall, the shared paternal ancestry of Kazakhs differentiates them from other Central Asian populations. In addition, all of them showed evidence of genetic influence by the 13(th) century CE Mongol Empire. Ultimately, the social and cultural traditions of the Kazakhs shaped their current pattern of genetic variation.     

A Possible Approach to Comparison of Survival Functions

Special numerical index for comparison of survival functions is proposed. The index is called by directed probabilistic semimetric. The examples of these semimetrics are presented. The procedure of the index estimating on sampled data is considered.     

Cost-effectiveness of a structured progressive task-oriented circuit class training programme to enhance walking competency after stroke: The protocol of the FIT-Stroke trial

Background  

Most patients who suffer a stroke experience reduced walking competency and health-related quality of life (HRQoL). A key factor in effective stroke rehabilitation is intensive, task-specific training. Recent studies suggest that intensive, patient-tailored training can be organized as a circuit with a series of task-oriented workstations.     

Effect of <Emphasis Type="Italic">NtDCN1</Emphasis> gene activated during embyogenesis on organogenesis in tobacco tissue culture

The role of NtDCN1 gene in organogenesis in the culture of tobacco (Nicotiana tabacum L.) somatic tissues was studied. This gene is specifically expressed in tobacco microspores induced for somatic embryogenesis. This gene knockout resulted in a disturbance of formation and development of embyoids from microspores. In leaf disks and calli derived from tobacco lines with active and inactivated NtDCN1 gene, we studied induction of shoots and roots. A comparative analysis of tobacco line morphogenetic responses in vitro showed that NtDCN1 gene inactivation enhanced shoot formation and suppressed rhizogenesis, whereas this gene reactivation returned organogenesis processes to control level. Difference between lines was manifested only at a definite ratio between exogenous hormones supplied. The involvement of NtDCN1 gene in line responses to exogenous auxin is discussed. The results obtained permit a supposition that the NtDCN1 gene is critical for regulation not only somatic embryogenesis but also organogenesis.     

Method of disinfecting plague-infected fleas in preparation for electron microscopic study

During fixation of fleas infected with plague agent (with preliminary cut heads, limbs and posterior part of the abdomen) in 2.5% glutaric dialdehyde or 2% osmium tetroxide their disinfection was obtained in two days. After double fixation with 2-hour exposure in each of these fixators disinfection of the material was acheived only after additional 2-day maintenance in 70% ethyl alcohol. Fleas, which had been placed into fixators or in 70% ethyl alcohol after double fixation without preliminary dissection, were disinfected completely only in 10 days.