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Type IV secretion (T4S) systems form the most common and versatile class of secretion systems in bacteria, capable of injecting both proteins and DNAs into host cells. T4S systems are typically composed of 12 components that form 2 major assemblies: the inner membrane complex embedded in the inner membrane and the core complex embedded in both the inner and outer membranes. Here we present the 3.3 Å-resolution cryo-electron microscopy model of the T4S system core complex from Xanthomonas citri , a phytopathogen that utilizes this system to kill bacterial competitors. An extensive mutational investigation was performed to probe the vast network of protein–protein interactions in this 1.13-MDa assembly. This structure expands our knowledge of the molecular details of T4S system organization, assembly and evolution. A combination of cryo-electron microscopy (cryo-EM) and targeted mutagenesis studies elucidates the structure and organization of the core complex of the type IV secretion system used by Xanthomonas citri to kill competing bacteria.

Viruses have transformed our understanding of mammalian RNA processing, including facilitating the discovery of the methyl-7-guanosine (m⁷G) cap on the 5′ end of RNAs. The m⁷G cap is required for RNAs to bind the eukaryotic translation initiation factor eIF4E and associate with the translation machinery across plant and animal kingdoms. The potyvirus-derived viral genome-linked protein (VPg) is covalently bound to the 5′ end of viral genomic RNA (gRNA) and associates with host eIF4E for successful infection. Divergent models to explain these observations proposed either an unknown mode of eIF4E engagement or a competition of VPg for the m⁷G cap-binding site. To dissect these possibilities, we resolved the structure of VPg, revealing a previously unknown 3-dimensional (3D) fold, and characterized the VPg–eIF4E complex using NMR and biophysical techniques. VPg directly bound the cap-binding site of eIF4E and competed for m⁷G cap analog binding. In human cells, VPg inhibited eIF4E-dependent RNA export, translation, and oncogenic transformation. Moreover, VPg formed trimeric complexes with eIF4E–eIF4G, eIF4E bound VPg–luciferase RNA conjugates, and these VPg–RNA conjugates were templates for translation. Informatic analyses revealed structural similarities between VPg and the human kinesin EG5. Consistently, EG5 directly bound eIF4E in a similar manner to VPg, demonstrating that this form of engagement is relevant beyond potyviruses. In all, we revealed an unprecedented modality for control and engagement of eIF4E and show that VPg–RNA conjugates functionally engage eIF4E. As such, potyvirus VPg provides a unique model system to interrogate eIF4E.

The dysregulation of translation contributes to many pathogenic conditions in humans. Discovering new translational mechanisms is important to understanding the diversity of this process and its potential mechanisms. Such mechanisms can be initially observed in viruses. With this in mind, we studied the viral protein genome-linked VPg factor from the largest genus of plant viruses. Studies in plants show that VPg binds to the eukaryotic translation initiation factor eIF4E for translation of viral RNAs. VPg contains no known eIF4E binding motifs and no sequence homology to any known proteins. Thus, as a first step in understanding the structural basis of this interaction, we carried out NMR assignments of the VPg from the potato virus Y potyvirus protein.

O presente artigo é oriundo de uma pesquisa em psicanálise e educação realizada no ambulatório infantojuvenil do Instituto de Psiquiatria da Universidade Federal do Rio de Janeiro (IPUB-UFRJ), através de uma parceria entre a Faculdade de Educação da UFRJ e a Faculdade de Educação da UFF. Parte da constatação que as condições sociais que sustentam o laço educativo e a transmissão têm sofrido grandes transformações nas últimas décadas. Tece uma reflexão a cerca do cenário contemporâneo sobretudo à luz dos trabalhos sobre mal-estar docente em psicanálise e educação no contexto brasileiro. Visa mapear o mal-estar na escolarização de crianças e adolescentes, mais especificamente a partir do discurso de educadores. Encontra nos ideais de aluno e de educação aspectos importantes para a análise do mal-estar.

A major component of phase II drug metabolism is the covalent addition of glucuronic acid to metabolites and xenobiotics. This activity is carried out by UDP-glucuronosyltransferases (UGT) which bind the UDP-glucuronic acid donor and catalyze the covalent addition of glucuronic acid sugar moieties onto a wide variety of substrates. UGTs play important roles in drug detoxification and were recently shown to act in an inducible form of multi-drug resistance in cancer patients. Despite their biological importance, structural understanding of these enzymes is limited. The C-terminal domain is identical for all UGT1A family members and required for binding to UDP-glucuronic acid as well as involved in contacts with substrates. Here, we report the backbone assignments for the C-terminal domain of UGT1A. These assignments are a critical tool for the development of a deeper biochemical understanding of substrate specificity and enzymatic activity.

Este texto abordar la operación de la adolescencia en el contexto de los movimientos sociales que tienen como característica subvertir discursos estatuidos. El trabajo de la adolescencia implica transformar lo que se ha recibido como herencia simbólica haciendo posible alguna apropiación singular de eso, incluso siempre marcada por algo de lo real que la trasciende y supera. El movimiento social que sirve de base para la discusión en el texto fue el denominado “ocupa escuela” reconocido como movimiento de las ocupaciones de escuelas por estudiantes de secundaria en Brasil entre el 2015 y el 2017 el análisis de ese movimiento es cruzado con hallazgos realizados en una investigación con adolescentes en Latinoamérica sobre nominación y cambios de nombres.

Resumo: Diante do alto índice de atos autolesivos em adolescentes no Brasil e no mundo, pretende-se analisar o apelo recorrente a esse recurso na adolescência, discutindo questões relativas ao laço social nele implicadas. Tal discussão será feita a partir do caso clínico de uma adolescente de 14 anos, encaminhado pela escola para o SPIA/IPUB-UFRJ e marcado pela presença da angústia e do desamparo, cujas possibilidades de inscrição psíquica e endereçamento parecem vacilar. O artigo é fruto de pesquisa em andamento sobre autolesões e suicídio na adolescência, que pretende contribuir para a construção de dispositivos, particularmente nos âmbitos da saúde e da educação, para intervir e manejar esse problema clínico-político de nossos tempos.

Resumo: Diante do alto índice de atos autolesivos em adolescentes no Brasil e no mundo, pretende-se analisar o apelo recorrente a esse recurso na adolescência, discutindo questões relativas ao laço social nele implicadas. Tal discussão será feita a partir do caso clínico de uma adolescente de 14 anos, encaminhado pela escola para o SPIA/IPUB-UFRJ e marcado pela presença da angústia e do desamparo, cujas possibilidades de inscrição psíquica e endereçamento parecem vacilar. O artigo é fruto de pesquisa em andamento sobre autolesões e suicídio na adolescência, que pretende contribuir para a construção de dispositivos, particularmente nos âmbitos da saúde e da educação, para intervir e manejar esse problema clínico-político de nossos tempos. Abstract: Given the high rate of self-injury among adolescents in Brazil and worldwide, this paper intends to analyze this resource’s recurrent use in adolescence, discussing issues related to the social bond implied in it. This discussion is based on the clinical case of a 14-year-old adolescent referred by her school to SPIA/IPUB-UFRJ. The youngster showed apparent anguish and helplessness, whose possibilities of psychic inscription and addressing seem to falter. The article results from ongoing research on self-injury and suicide in adolescence, which aims to contribute to developing strategies, particularly in the fields of health and education, to intervene and manage this clinical-political problem of our times.

a-Amylase production by thermophilic Bacillus sp strain SMIA-2 cultivated in liquid cultures containing soluble starch as a carbon source and supplemented with 0.05% whey protein and 0.2% peptone reached a maximum activity at 32 h, with levels of 37 U/mL. Studies on the amylase characterization revealed that the optimum temperature of this enzyme was 90ºC. The enzyme was stable for 1 h at temperatures ranging from 40-50ºC while at 90ºC, 66% of its maximum activity was lost. However, in the presence of 5 mM CaCl2, the enzyme was stable at 90ºC for 30 min and retained about 58% residual activity after 1 h. The optimum pH of the enzyme was found to be 8.5. After incubation of enzyme for 2 h at pH 9.5 and 11.0 was observed a decrease of about 6.3% and 16.5% of its original activity. At pH 6.0 the enzyme lost about 36% of its original activity. The enzyme was strongly inhibited by Co2+, Cu2+ and Ba2+, but less affected by Mg2+, Na+ and K+. In the presence of 2.0 M NaCl, 63% of amylase activity was retained after 2 h incubation at 45ºC. The amylase exhibited more than 70% activity when incubated for 1 h at 50ºC with sodium dodecyl sulphate. However, very little residual activity was obtained with sodium hypochlorite and with hydrogen peroxide the enzyme was completely inhibited. The compatibility of Bacillus sp SMIA-2 amylase with certain commercial detergents was shown to be good as the enzyme retained 86%, 85% and 75% of its activity after 20 min incubation at 50ºC in the presence of the detergent brands Omo®, Campeiro® and Tide®, respectively.

The text presents the results of a market research on black representation at Mauricio de Sousa Produções (MSP). Theoretical references were applied to the representation of historically discriminated groups, such as Cirne (1982), Agostinho (2017) and Chinen (2019) and to the study of Information Design, with Padua, Dias and Lima (2015) and Sá (2016), which allowed the construction of a infographic to illustrate the collected data. We investigated the appearance of prominent black characters on the covers of Turma da Mônica magazines, from the beginnings that preceded the explicit adoption of decolonial thinking to current editions, as well as pertinent numbers on articles already published on the subject investigated, extracted from CAPES Journal Portal (2020). The graphic piece produced presents a new trend by the studio in accentuating the presence of Afro-descendants in its editorial products, as well as confirming the lack of accessible studies on blacks in national comics El texto presenta los resultados de una investigación de mercado sobre la representación negra en Mauricio de Sousa Produções. Se aplicaron referencias teóricas a la representación de grupos históricamente discriminados, como Cirne (1982), Agostinho (2017) y Chinen (2019) y al estudio de Diseño de Información, con Padua, Dias y Lima (2015) y Sá (2016). , lo que permitió la construcción de una infografía temática para ilustrar los datos recopilados. Se investigó la aparición de personajes negros prominentes en las portadas de las revistas Turma da Mônica, desde los inicios que precedieron a una visión “políticamente correcta” hasta las ediciones actuales, así como números relevantes sobre artículos ya publicados sobre el tema investigado, extraídos de la Revista CAPES. Portal (2020). La pieza gráfica producida presenta una nueva tendencia del estudio al acentuar la presencia de afrodescendientes en sus productos editoriales, así como confirmar la falta de estudios accesibles sobre los negros en los cómics nacionales. O texto apresenta os resultados de uma pesquisa mercadológica sobre a representatividade negra na Mauricio de Sousa Produções (MSP). Foram aplicados referenciais teóricos alusivos à representação de grupos historicamente descriminados, a exemplo de Cirne (1982), Agostinho (2017) e Chinen (2019) e ao estudo do Design da Informação, com Padua, Dias e Lima (2015) e Sá (2016), que permitiram construir uma infografia para ilustrar os dados coletados. Investigou-se a aparição de personagens negros de proeminência nas capas das revistas da Turma da Mônica, dos primórdios que antecederam a adoção explícita do pensamento decolonial às edições da atualidade, assim como números pertinentes sobre os artigos já publicados sobre a temática investigada, extraídos do Portal de Periódicos da CAPES (2020). A peça gráfica produzida apresenta uma nova tendência do estúdio em acentuar a presença afrodescendente em seus produtos editoriais, assim como ratificar a carência de estudos acessíveis sobre o negro nos quadrinhos nacionais