Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.7.1.2 (nitrate reductase)
 3,861 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A 13-kb genomic region of Paracoccus dentrificans GB17 is involved in lithotrophic thiosulfate oxidation. Adjacent to the previously reported soxB gene (C. Wodara, S. Kostka, M. Egert, D. P. Kelly, and C. G. Friedrich, J. Bacteriol. 176:6188-6191, 1994), 3.7 kb were sequenced. Sequence analysis revealed four additional open reading frames, soxCDEF. soxC coded for a 430-amino-acid polypeptide with an Mr of 47,339 that included a putative signal peptide of 40 amino acids (Mr of 3,599) with a RR motif present in periplasmic proteins with complex redox centers. The mature soxC gene product exhibited high amino acid sequence similarity to the eukaryotic molybdoenzyme sulfite oxidase and to nitrate reductase. We constructed a mutant, GBsoxC delta, carrying an in-frame deletion in soxC which covered a region possibly coding for the molybdenum cofactor binding domain. GBsoxC delta was unable to grow lithoautotrophically with thiosulfate but grew well with nitrate as a nitrogen source or as an electron acceptor. Whole cells and cell extracts of mutant GBsoxC delta contained 10% of the thiosulfate-oxidizing activity of the wild type. Only a marginal rate of sulfite-dependent cytochrome c reduction was observed from cell extracts of mutant GBsoxC delta. These results demonstrated that sulfite dehydrogenase was essential for growth with thiosulfate of P. dentrificans GB17. soxD coded for a periplasmic diheme c-type cytochrome of 384 amino acids (Mr of 39,983) containing a putative signal peptide with an Mr of 2,363. soxE coded for a periplasmic monoheme c-type cytochrome of 236 amino acids (Mr of 25,926) containing a putative signal peptide with an Mr of 1,833. SoxD and SoxE were highly identical to c-type cytochromes of P. denitrificans and other organisms. soxF revealed an incomplete open reading frame coding for a peptide of 247 amino acids with a putative signal peptide (Mr of 2,629). The deduced amino acid sequence of soxF was 47% identical and 70% similar to the sequence of the flavoprotein of flavocytochrome c of Chromatium vinosum, suggesting the involvement of the flavoprotein in thiosulfate oxidation of P. denitrificans GB17.
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PMID:Cloning and characterization of sulfite dehydrogenase, two c-type cytochromes, and a flavoprotein of Paracoccus denitrificans GB17: essential role of sulfite dehydrogenase in lithotrophic sulfur oxidation. 926 Sep 41

During the past decades, tremendous advances have been made in the possibilities to study the diversity of microbial communities in the environment. The development of methods to study these communities on the basis of 16S rRNA gene sequences analysis was a first step into the molecular analysis of environmental communities and the study of biodiversity in natural habitats. A new dimension in this field was reached with the introduction of functional genes of ecological importance and the establishment of genetic tools to study the diversity of functional microbial groups and their responses to environmental factors. Functional gene approaches are excellent tools to study the diversity of a particular function and to demonstrate changes in the composition of prokaryote communities contributing to this function. The phylogeny of many functional genes largely correlates with that of the 16S rRNA gene, and microbial species may be identified on the basis of functional gene sequences. Functional genes are perfectly suited to link culture-based microbiological work with environmental molecular genetic studies. In this review, the development of functional gene studies in environmental microbiology is highlighted with examples of genes relevant for important ecophysiological functions. Examples are presented for bacterial photosynthesis and two types of anoxygenic phototrophic bacteria, with genes of the Fenna-Matthews-Olson-protein (fmoA) as target for the green sulfur bacteria and of two reaction center proteins (pufLM) for the phototrophic purple bacteria, with genes of adenosine-5'phosphosulfate (APS) reductase (aprA), sulfate thioesterase (soxB) and dissimilatory sulfite reductase (dsrAB) for sulfur oxidizing and sulfate reducing bacteria, with genes of ammonia monooxygenase (amoA) for nitrifying/ammonia-oxidizing bacteria, with genes of particulate nitrate reductase and nitrite reductases (narH/G, nirS, nirK) for denitrifying bacteria and with genes of methane monooxygenase (pmoA) for methane oxidizing bacteria.
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PMID:New Dimensions in Microbial Ecology-Functional Genes in Studies to Unravel the Biodiversity and Role of Functional Microbial Groups in the Environment. 2768 13