How to change the oligomeric state of a circular protein assembly: switch from 11-subunit to 12-subunit TRAP suggests a general mechanism

Many critical cellular functions are performed by multisubunit circular protein oligomers whose internal geometry has evolved to meet functional requirements. The subunit number is arguably the most critical parameter of a circular protein assembly, affecting the internal and external diameters of the assembly and often impacting on the protein's function. Although accurate structural information has been obtained for several circular proteins, a lack of accurate information on alternative oligomeric states has prevented engineering such transitions. In this study we used the bacterial transcription regulator TRAP as a model system to investigate the features that define the oligomeric state of a circular protein and to question how the subunit number could be manipulated.We find that while Bacillus subtilis and Bacillus stearothermophilus TRAP form 11-subunit oligomers, the Bacillus halodurans TRAP exclusively forms 12-subunit assemblies. Significantly, the two states of TRAP are related by a simple rigid body rotation of individual subunits around inter-subunit axes. We tested if such a rotation could be induced by insertion or deletion mutations at the subunit interface. Using wild type 11-subunit TRAP, we demonstrate that removal of five C-terminal residues at the outer side of the inter-subunit axis or extension of an amino acid side chain at the opposite, inner side, increased the subunit number from 11 to 12. Our findings are supported by crystal structures of TRAP oligomers and by native mass spectrometry data.The subunit number of the TRAP oligomer can be manipulated by introducing deletion or addition mutations at the subunit interface. An analysis of available and emerging structural data on alternative oligomeric states indicates that the same principles may also apply to the subunit number of other circular assemblies suggesting that the deletion/addition approach could be used generally to engineer transitions between different oligomeric states

Fukalite: an example of OD structure with two-dimensional disorder

The real crystal structure of fukalite, Ca4Si2O 6(OH)2(CO3), was solved by means of the application of order-disorder (OD) theory and was refined through synchrotron radiation diffraction data from a single crystal. The examined sample came from the Gumeshevsk skarn copper porphyry deposit in the Central Urals, Russia. The selected crystal displays diffraction patterns characterized by strong reflections, which pointed to an orthorhombic sub-structure (the "family structure" in the OD terminology), and additional weaker reflections that correspond to a monoclinic real structure. The refined cell parameters are a = 7.573(3), b = 23.364(5), c = 11.544(4) Å, β = 109.15(1)°, space group P21/c. This unit cell corresponds to one of the six possible maximum degree of order (MDO) polytypes, as obtained by applying the OD procedure. The derivation of the six MDO polytypes is presented in the Appendix1. The intensity data were collected at the Elettra synchrotron facility (Trieste, Italy); the structure refinement converged to R = 0.0342 for 1848 reflections with I > 2σ(I) and 0.0352 for all 1958 data. The structure of fukalite may be described as formed by distinct structural modules: a calcium polyhedral framework, formed by tobermorite-type polyhedral layers alternating along b with tilleyitetype zigzag polyhedral layers; silicate chains with repeat every fifth tetrahedron, running along a and linked to the calcium polyhedral layers on opposite sides; and finally rows of CO3 groups parallel to (100) and stacked along a

Рентгенометрический анализ кинематики L4-L5 И L5-S1 позвоночных сегментов в III стадии дегенеративного процесса

ПОЗВОНОЧНИКА БОЛЕЗНИОСТЕОХОНДРОЗОСТЕОХОНДРИТГРЫЖА МЕЖПОЗВОНОЧНОГО ДИСКАМЕЖПОЗВОНКОВОГО ДИСКА СМЕЩЕНИЕРЕНТГЕНОГРАФИ

Ferroplasmas: Magnetic Dust Dynamics in a Conducting Fluid

We consider a dusty plasma, in which the dust particles have a magnetic dipole moment. A Hall-MHD type of model, generalized to account for the intrinsic magnetization, is derived. The model is shown to be energy conserving, and the energy density and flux is derived. The general dispersion relation is then derived, and we show that kinetic Alfv\'en waves exhibit an instability for a low temperature and high density plasma. We discuss the implication of our results.Comment: 6 pages, 1 figur

Translation and cross-cultural adaptation into italian of the self-administered FLARE-RA questionnaire for rheumatoid arthritis

The aim was to provide a translation into Italian with cross-cultural adaptation of the French FLARE-Rheumatoid Arthritis (RA) questionnaire, and to test its acceptability, feasibility, reliability and construct validity in a single-centre cohort study. The French version of the FLARE-RA questionnaire was cross-culturally adapted and translated into Italian following an established forward\u2013backward translation procedure, with independent translations and backtranslations. To validate the Italian version we tested the internal validity with Cronbach\u2019s alpha, test-retest reliability with the intraclass correlation coefficient, agreement between assessments with Bland-Altman plots and construct validity with Spearman\u2019s correlation coefficients. The questionnaire was tested on 283 consecutive RA outpatients (mean age 56.1\ub1}13.9 years, 226/283 females, median disease duration 12.6 years ranging from 0.2 to 70.6). For the global score (11 items) the Cronbach\u2019s alpha coefficient was 0.94. The intraclass correlation coefficient was 0.87 (95% CI, 0.76-0.96). The correlation of FLARE-RA global score was 0.59 (95% CI, 0.50-0.66) with the Disease Activity Score on 28 joints, 0.63 (95% CI, 0.55-0.71) with the Simplified Disease Activity Index, 0.77 (95% CI, 0.71-0.83) with the RA Impact of Disease and 0.67 (95% CI, 0.59-0.73) with the Health Assessment Questionnaire. The Italian version of the FLARE-RA is feasible, brief and easy to administer. The translated and cross-cultural adapted showed accordingly to be valid and reliable. This questionnaire has some practical advantages, such as clarity, comprehensiveness, simplicity, and a minimum filling time. The development of cross-cultural adapted questionnaires in different languages is of pivotal importance to obtain standardized and comparable data across countries

La investigación en ciencia y tecnología de alimentos. Situación actual y tendencias

Este informe, elaborado a requerimiento del Observatorio Iberoamericano de la Ciencia, la Tecnología y la Sociedad del Centro de Altos Estudios Universitarios de la OEI, presenta un panorama detallado de la investigación científica y el desarrollo tecnológico en el área de ciencia y tecnología de alimentos en Iberoamérica. Se ha buscado también dar cuenta de las principales tendencias registradas a nivel mundial en esta temática y su impacto y correlato con lo observado a nivel regional. Las fuentes de información utilizadas a tal fin han sido las publicaciones científicas registradas en la base de datos bibliométrica Science Citation Index y las patentes de invención tramitadas a través del convenio PCT. La identificación de estos registros se realizó bajo la supervisión de expertos regionales en este campo. Se trata de la misma metodología utilizada en estudios previos sobre la nanotecnología y la biotecnología, publicados en 2008 y 2009, respectivamente. Este trabajo presenta un panorama general de la producción científica en ciencia y tecnología de alimentos a nivel mundial y regional, con un detallado acercamiento a los patrones de colaboración entre países. Se han aplicado para ello herramientas de análisis de redes que muestran patrones mundiales y particularidades regionales en la investigación colaborativa. Se abordan también los principales temas estudiadas por los grupos de investigación de la región. Posteriormente, se ofrecen detalles sobre la evolución de la producción de conocimiento de aplicación industrial a través de las patentes de invención. Este estudio incluye las tendencias a nivel mundial y regional, tanto en la titularidad como en la participación de inventores iberoamericanos. Dada la complejidad de este campo, el estudio incluye también un análisis detallado de los campos de aplicación de las patentes de la región y de los principales países que la integran. Entre las evidencias obtenidas se destaca el importante nivel de especialización de algunos países de la región en esta temática. Ese fenómeno es muy claro en el caso español, que alcanza el segundo lugar en cuanto a volumen de publicaciones en 2009. A nivel latinoamericano, Argentina también presenta una marcada especialización en este tema, acorde a la importancia del sector a nivel nacional. El panorama resulta muy diferente en el análisis de las patentes, donde los países iberoamericanos tienen una presencia mucho menor. En este trabajo se pueden ver varios indicios de la falta de consolidación del sistema productivo de alimentos a nivel regional, que no acompaña el creciente desarrollo de la investigación científica.Fil: Barrere, Rodolfo; Argentina.Fil: D'Onofrio, María Guillermina; Argentina.Fil: Tignino, María Victoria; Argentina.Fil: Merlino-Santesteban, Cristian. Universidad Nacional de Mar del Plata. Facultad de Ciencias Económicas y Sociales; Argentina.Fil: Matas, Lautaro; Argentina.Fil: Añon, María Cristina. CIDCA UNLP-CONICET; Argentina.Fil: Martínez, Estela N. CIDCA UNLP-CONICET; Argentina.Fil: Martínez Vidal, José Luis. Universidad de Almería; España

The association between hip-shoulder separation angles and technique characteristics in world-class high jumpers

Hip-shoulder separation (H-Ssep) has been widely researched in many sporting activities (e.g., golf) to provide information on the contribution of torso rotation to performance and injury. Although it is necessary for high jumpers to generate significant long-axis rotation to successfully clear the bar, limited information exists on H-Ssep for high jump athletes. As such, this study aimed to a) characterize the H-Ssep of world-class high jump athletes during competition, b) determine if differences exist between male and female athletes and c) to examine the relationship between H-Ssep and the biomechanical parameters used to describe high jump technique. Twenty-nine world-class high jumpers (17 males, 12 females) were recorded (120-200 Hz) during the 2017 and 2018 World Athletics Championship finals. H-Ssep was quantified at touchdown (TD) and take-off (TO) following manual digitizing (SIMI motion) and a number of other common biomechanical parameters were computed. The observed levels of H-Ssep at TD (−46 ± 12o) and TO (16 ± 11o) were in line with those reported previously for other sports. The magnitude of H-Ssep varied between individuals and showed significant associations with other approach and take-off characteristics. Significant differences in H-Ssep were not evident between male and female athletes despite significant differences in other performance- and technique-related parameters. These findings highlight the divergent take-off characteristics of world-class performers and their reliance on hip-shoulder interactions when generating long axis rotation. Coaches should be mindful of the mechanical and physical consequences of H-Ssep when developing technical models, conditioning interventions and coaching strategies