26 documents found, page 1 of 3
The role of the Yap5 transcription factor in remodeling gene expression in resp...
Pimentel, Catarina; Vicente, Cristina; Menezes, Regina Andrade; Caetano, Soraia; Carreto, Laura; Rodrigues-Pousada, ClaudinaThe budding yeast Saccharomyces cerevisiae has developed several mechanisms to avoid either the drastic consequences of iron deprivation or the toxic effects of iron excess. In this work, we analysed the global gene expression changes occurring in yeast cells undergoing iron overload. Several genes directly or indirectly involved in iron homeostasis showed altered expression and the relevance of these changes a...
Desulfovibrio gigas neelaredoxin: a novel superoxide dismutase integrated in a ...
Silva, Gabriela; Oliveira, Solange; Gomes, Cláudio; Pacheco, Isabel; Liu, M.Y.; Xavier, António V.; Teixeira, Miguel; LeGall, JeanNeelaredoxin, a small non-heme blue iron protein from the sulfate-reducing bacterium Desulfovibrio gigas [Chen, L., Sharma, P., LeGall, J., Mariano, A.M., Teixeira M. and Xavier, A.V. (1994) Eur. J. Biochem. 226, 613±618] is shown to be encoded by a polycistronic unit which contains two additional open reading frames (ORF-1 and ORF-2) coding for chemotaxis-like proteins. ORF-1 has domains highly homologous with...
A DNA fragment of Desulfovibrio gigas genome containing replication origin rela...
Broco, Manuela; Oliveira, Solange; Silva, Gabriela; Agostinho, Marta; Rodrigues-Pousada, ClaudinaThe nucleotide sequence of a 10,772 base pair (bp) region from Desulfovibrio gigas genome was determined. This sequence, which is adjacent to the region containing the coding units for the metalloproteins rubredoxin-oxygen oxidoreductase (ROO) and rubredoxin, includes the flavodoxin gene. Additionally, it also contains four open reading frames (ORFs) related to genes frequently found in replication origin regio...
Molecular cloning of the gene encoding flavoredoxin, a flavoprotein from Desulf...
Agostinho, Marta; Oliveira, Solange; Broco, Manuela; Liu, M.Y.; LeGall, Jean; Rodrigues-Pousada, ClaudinaSulfate-reducing bacteria are rich in unique redox proteins and electron carriers that participate in a variety of essential pathways. Several studies have been carried out to characterize these proteins, but the structure and function of many are poorly understood. Many Desulfovibrio species can grow using hydrogen as the sole energy source, indicating that the oxidation of hydrogen with sulfite as the termina...
Structure of a dioxygen reduction enzyme from Desulfovibrio gigas
Frazão, Carlos; Silva, Gabriela; Gomes, Claudio; Matias, Pedro; Coelho, R; Sieker, L; Macedo, S; Liu, MY; Oliveira, Solange; Teixeira, MiguelDesulfovibrio gigas is a strict anaerobe that contains a well-characterized metabolic pathway that enables it to survive transient contacts with oxygen. The terminal enzyme in this pathway, rubredoxin:oxygen oxidoreductase (ROO) reduces oxygen to water in a direct and safe way. The 2.5 Angstrom resolution crystal structure of ROO shows that each monomer of this homodimeric enzyme consists of a novel combination...
Analysis of the Desulfovibrio gigas transcriptional unit containing rubredoxin ...
Silva, Gabriela; Oliveira, Solange; LeGall, Jean; Xavier, António V; Rodrigues-Pousada, ClaudinaRubredoxin-oxygen oxidoreductase, an 86-kDa homodimeric flavoprotein, is the final component of a soluble electron transfer chain that couples NADH oxidation with oxygen reduction to water from the sulfate-reducing bacterium Desulfovibrio gigas. A 4.2-kb fragment Of D. gigas chromosomal DNA containing the roo gene and the rubredoxin gene was sequenced, Additional open reading frames designated as ORF-1, ORF-2, ...
Docking and electron transfer studies between rubredoxin and rubredoxin : oxyge...
Victor, Bruno; Vicente, João; Rodrigues, Rute; Oliveira, Solange; Rodrigues-Pousada, Claudina; Frazão, Carlos; Gomes, Cláudio; Teixeira, MiguelAbstract: The interaction and electron transfer (ET) between rubredoxin (Rd) and rubredoxin: oxygen oxidoreductase (ROO) from Desulfovibrio gigas is studied by molecular modelling techniques. Experimental kinetic assays using recombinant proteins show that the Rd reoxidation by ROO displays a bell-shaped dependence on ionic strength, suggesting a non-trivial electrostatic dependence of the interaction between t...
A novel membrane-bound Ech [NiFe] hydrogenase in Desulfovibrio gigas
Rodrigues, Rute; Valente, Filipa; Pereira, Inês; Oliveira, Solange; Rodrigues-Pousada, ClaudinaAbstract: In the present study, we report the identification of an operon with six coding regions for a multisubunit membrane-bound [NiFe] hydrogenase in the genome of Desulfovibrio gigas. Sequence analysis of the deduced polypeptides reveals a high similarity to subunits of proteins belonging to the family of Ech hydrogenases. The operon is organised similarly to the operon coding for the Ech hydrogenase from ...
Molecular determinants for FMN-binding in Desulfovibrio gigas flavoredoxin
Broco, Manuela; Soares, Claudio M.; Oliveira, Solange; Mayhew, Stephen G; Rodrigues-Pousada, ClaudinaAbstract: Flavoredoxin participates in Desulfovibrio gigas thiosulfate reduction pathway. Its 3-dimensional model was generated allowing the oxidized riboflavin-5'-phosphate (FMN) site to be predicted. Residues likely to be involved in FMN-binding were identified (N29, W35, T56, K92, H131 and F164) and mutated to alanine. Fluorescence titration with apoprotein showed that FMN is strongly bound in the wild-type ...
Desulfovibrio gigas flavodiiron protein affords protection against nitrosative ...
Rodrigues, Rute; Vicente, João B.; Félix, Rute; Oliveira, Solange; Teixeira, Miguel; Rodrigues-Pousada, ClaudinaAbstract: Desulfovibrio gigas flavodiiron protein (FDP), rubredoxin: oxygen oxidoreductase (ROO), was proposed to be the terminal oxidase of a soluble electron transfer chain coupling NADH oxidation to oxygen reduction. However, several members from the FDP family, to which ROO belongs, revealed nitric oxide (NO) reductase activity. Therefore, the protection afforded by ROO against the cytotoxic effects of NO w...