Letteratura scientifica selezionata sul tema "Crécy"

ABSTRACT Most organisms form Cys-tRNACys, an essential component for protein synthesis, through the action of cysteinyl-tRNA synthetase (CysRS). However, the genomes of Methanocaldococcus jannaschii, Methanothermobacter thermautotrophicus, and Methanopyrus kandleri do not contain a recognizable cysS gene encoding CysRS. It was reported that M. jannaschii prolyl-tRNA synthetase (C. Stathopoulos, T. Li, R. Longman, U. C. Vothknecht, H. D. Becker, M. Ibba, and D. Söll, Science 287:479-482, 2000; R. S. Lipman, K. R. Sowers, and Y. M. Hou, Biochemistry 39:7792-7798, 2000) or the M. jannaschii MJ1477 protein (C. Fabrega, M. A. Farrow, B. Mukhopadhyay, V. de Crécy-Lagard, A. R. Ortiz, and P. Schimmel, Nature 411:110-114, 2001) provides the “missing” CysRS activity for in vivo Cys-tRNACys formation. These conclusions were supported by complementation of temperature-sensitive Escherichia coli cysS(Ts) strain UQ818 with archaeal proS genes (encoding prolyl-tRNA synthetase) or with the Deinococcus radiodurans DR0705 gene, the ortholog of the MJ1477 gene. Here we show that E. coli UQ818 harbors a mutation (V27E) in CysRS; the largest differences compared to the wild-type enzyme are a fourfold increase in the Km for cysteine and a ninefold reduction in the k cat for ATP. While transformants of E. coli UQ818 with archaeal and bacterial cysS genes grew at a nonpermissive temperature, growth was also supported by elevated intracellular cysteine levels, e.g., by transformation with an E. coli cysE allele (encoding serine acetyltransferase) or by the addition of cysteine to the culture medium. An E. coli cysS deletion strain permitted a stringent complementation test; growth could be supported only by archaeal or bacterial cysS genes and not by archaeal proS genes or the D. radiodurans DR0705 gene. Construction of a D. radiodurans DR0705 deletion strain showed this gene to be dispensable. However, attempts to delete D. radiodurans cysS failed, suggesting that this is an essential Deinococcus gene. These results imply that it is not established that proS or MJ1477 gene products catalyze Cys-tRNACys synthesis in M. jannaschii. Thus, the mechanism of Cys-tRNACys formation in M. jannaschii still remains to be discovered.

RESUMO: Este artigo visa apresentar a realidade daqueles que vivem em um assentamento através do olhar da jovem Joice dos Santos Silva, de vinte anos que vive no assentamento Florestan Fernandes, localizado no povoado Oroco, em Canindé do São Francisco-SE. Uma comunidade que vive na região circundante ao Rio São Francisco. Através da história oral analisamos a trajetória de vida e as expectativas de futuro em uma relação de interdependência geopolítica social com seu território. Este artigo teve como metodologia a análise de entrevista e relato oral na comunidade.
 
 Palavras-Chave: História oral, Joice dos Santos Silva, História local, assentamento, Canindé do São Francisco-SE.

This Voicing is concerned with issues of voice perception, subjectivity and gender construction and explores the possibility of addressing them through the extended voice. It gives an account of the experience of ‘Voice X’, a singer who suffered from dysphoria, tracking the gendering process of their sounding voice through adolescence and its implications with personhood and social inclusion. I argue that the extended voice can problematize the gap between that which we say and what is said by the ‘grain’ of our voice. Focusing on the meaning potential of creak ‐ taken as an example of ‘another voice’ ‐ this practice research piece puts forward the argument that any extra-normal voicing has an implicit drag potential, made explicit each time a body to-be-looked-at and a voice to-be-listened-to do not seem to match. In conclusion, I introduce the idea of ‘minor creak’ as a queer space for vocal exploration.