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Galvão,C.W.; Souza,E.M.; Etto,R.M.; Pedrosa,F.O.; Chubatsu,L.S.; Yates,M.G.; Schumacher,J.; Buck,M.; Steffens,M.B.R.. |
DNA repair is crucial to the survival of all organisms. The bacterial RecA protein is a central component in the SOS response and in recombinational and SOS DNA repairs. The RecX protein has been characterized as a negative modulator of RecA activity in many bacteria. The recA and recX genes of Herbaspirillum seropedicae constitute a single operon, and evidence suggests that RecX participates in SOS repair. In the present study, we show that the H. seropedicae RecX protein (RecX Hs) can interact with the H. seropedicaeRecA protein (RecA Hs) and that RecA Hs possesses ATP binding, ATP hydrolyzing and DNA strand exchange activities. RecX Hs inhibited 90% of the RecA Hs DNA strand exchange activity even when present in a 50-fold lower molar concentration than... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: RecA; RecX; Herbaspirillum seropedicae; SOS repair. |
Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2012001200004 |
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Nishikawa,C.Y.; Araújo,L.M.; Kadowaki,M.A.S.; Monteiro,R.A.; Steffens,M.B.R.; Pedrosa,F.O.; Souza,E.M.; Chubatsu,L.S.. |
Azospirillum brasilense is a nitrogen-fixing bacterium associated with important agricultural crops such as rice, wheat and maize. The expression of genes responsible for nitrogen fixation (nif genes) in this bacterium is dependent on the transcriptional activator NifA. This protein contains three structural domains: the N-terminal domain is responsible for the negative control by fixed nitrogen; the central domain interacts with the RNA polymerase σ54 co-factor and the C-terminal domain is involved in DNA binding. The central and C-terminal domains are linked by the interdomain linker (IDL). A conserved four-cysteine motif encompassing the end of the central domain and the IDL is probably involved in the oxygen-sensitivity of NifA. In the present study,... |
Tipo: Info:eu-repo/semantics/other |
Palavras-chave: Biological nitrogen fixation; Azospirillum brasilense; NifA protein. |
Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2012000200004 |
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