scholarly journals Rhizobium meliloti genes involved in sulfate activation: the two copies of nodPQ and a new locus, saa.

Genetics ◽  
1992 ◽  
Vol 132 (4) ◽  
pp. 899-909 ◽  
Author(s):  
J S Schwedock ◽  
S R Long
Keyword(s):  
Host Plants ◽  
Rhizobium Meliloti ◽  
Atp Sulfurylase ◽  
Plant Host ◽  
Nod Factor ◽  
Aps Kinase ◽  
Specific Host ◽  
Cysteine Synthesis ◽  
Sulfate Activation ◽  
Leguminous Host

Abstract The nitrogen-fixing symbiont Rhizobium meliloti establishes nodules on leguminous host plants. Nodulation (nod) genes used for this process are located in a cluster on the pSym-a megaplasmid of R. meliloti. These genes include nodP and nodQ (here termed nodPQ), which encode ATP sulfurylase and APS kinase, enzymes that catalyze the conversion of ATP and SO(4)2- into the activated sulfate form 3'-phosphoadenosine 5'-phosphosulfate (PAPS), an intermediate in cysteine synthesis. In Rhizobium, PAPS is also a precursor for sulfated and N-acylated oligosaccharide Nod-factor signals that cause symbiotic responses on specific host plants such as alfalfa. We previously found a highly conserved second copy of nodPQ in R. meliloti. We report here the mapping and cloning of this second copy, and its location on the second megaplasmid, pSym-b. The function of nodP2Q2 is equivalent to that of nodP1Q1 in complementation tests of R. meliloti and Escherichia coli mutants in ATP sulfurylase and adenosine 5'-phosphosulfate (APS) kinase. Mutations in nodP2Q2 do not have as severe an effect on symbiosis or plant host range as do those in nodP1Q1, however, possibly reflecting differences in expression and/or channeling of metabolites to specific enzymes involved in sulfate transfer. Strains mutated or deleted for both copies of nodQ are severely defective in symbiotic phenotypes, but remain prototrophic. This suggests the existence in R. meliloti of a third locus for ATP sulfurylase and APS kinase activities. We have found a new locus saa (sulfur amino acid), which may also encode these activities.

The Mycobacterium tuberculosis cysD and cysNC genes form a stress-induced operon that encodes a tri-functional sulfate-activating complex

Microbiology ◽  
2004 ◽  
Vol 150 (6) ◽  
pp. 1681-1686 ◽  
Author(s):  
Rachel Pinto ◽  
Quing Xui Tang ◽  
Warwick J. Britton ◽  
Thomas S. Leyh ◽  
James A. Triccas
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Sulfur Metabolism ◽  
Enzyme Complex ◽  
Sulfur Assimilation ◽  
Atp Sulfurylase ◽  
Catalytic Activities ◽  
Disease Relevance ◽  
Anti Oxidant ◽  
Sulfate Activation ◽  
Reductive Assimilation

Sulfur metabolism has been implicated in the virulence, antibiotic resistance and anti-oxidant defence of Mycobacterium tuberculosis. Despite its human disease relevance, sulfur metabolism in mycobacteria has not yet been fully characterized. ATP sulfurylase catalyses the synthesis of activated sulfate (adenosine 5′-phosphosulfate, APS), the first step in the reductive assimilation of sulfate. Expression of the M. tuberculosis cysD gene, predicted to encode the adenylyl-transferase subunit of ATP sulfurylase, is upregulated by the bacilli inside its preferred host, the macrophage. This study demonstrates that cysD and cysNC orthologues exist in M. tuberculosis and constitute an operon whose expression is induced by sulfur limitation and repressed by the presence of cysteine, a major end-product of sulfur assimilation. The cysDNC genes are also induced upon exposure to oxidative stress, suggesting regulation of sulfur assimilation by M. tuberculosis in response to toxic oxidants. To ensure that the cysDNC operon encoded the activities predicted by its primary sequence, and to begin to characterize the products of the operon, they were expressed in Escherichia coli, purified to homogeneity, and tested for their catalytic activities. The CysD and CysNC proteins were shown to form a multifunctional enzyme complex that exhibits the three linked catalytic activities that constitute the sulfate activation pathway.

Degradation of Nodulation Signals from Rhizobium meliloti by its Host Plants

1997 ◽  
pp. 43-46 ◽  
Author(s):  
Christian Staehelin ◽  
Maud Vanney ◽  
Fabrice Foucher ◽  
Eva Kondorosi ◽  
Michael Schultze ◽  
...  
Keyword(s):  
Host Plants ◽  
Rhizobium Meliloti

scholarly journals Identification of a Third Sulfate Activation System in Sinorhizobium sp. Strain BR816: the CysDN Sulfate Activation Complex

2003 ◽  
Vol 69 (4) ◽  
pp. 2006-2014 ◽  
Author(s):  
Carla Snoeck ◽  
Christel Verreth ◽  
Ismael Hernández-Lucas ◽  
Esperanza Martínez-Romero ◽  
Jos Vanderleyden
Keyword(s):  
Growth Characteristics ◽  
Open Reading Frames ◽  
Lag Phase ◽  
Sulfur Source ◽  
Nod Factors ◽  
Wild Type ◽  
Triple Mutant ◽  
Nod Factor ◽  
Growth Defects ◽  
Sulfate Activation

ABSTRACT Sinorhizobium sp. strain BR816 possesses two nodPQ copies, providing activated sulfate (3′-phosphoadenosine-5′-phosphosulfate [PAPS]) needed for the biosynthesis of sulfated Nod factors. It was previously shown that the Nod factors synthesized by a nodPQ double mutant are not structurally different from those of the wild-type strain. In this study, we describe the characterization of a third sulfate activation locus. Two open reading frames were fully characterized and displayed the highest similarity with the Sinorhizobium meliloti housekeeping ATP sulfurylase subunits, encoded by the cysDN genes. The growth characteristics as well as the levels of Nod factor sulfation of a cysD mutant (FAJ1600) and a nodP1 nodQ2 cysD triple mutant (FAJ1604) were determined. FAJ1600 shows a prolonged lag phase only with inorganic sulfate as the sole sulfur source, compared to the wild-type parent. On the other hand, FAJ1604 requires cysteine for growth and produces sulfate-free Nod factors. Apigenin-induced nod gene expression for Nod factor synthesis does not influence the growth characteristics of any of the strains studied in the presence of different sulfur sources. In this way, it could be demonstrated that the “household” CysDN sulfate activation complex of Sinorhizobium sp. strain BR816 can additionally ensure Nod factor sulfation, whereas the symbiotic PAPS pool, generated by the nodPQ sulfate activation loci, can be engaged for sulfation of amino acids. Finally, our results show that rhizobial growth defects are likely the reason for a decreased nitrogen fixation capacity of bean plants inoculated with cysD mutant strains, which can be restored by adding methionine to the plant nutrient solution.

scholarly journals The Cpc1 Regulator of the Cross-Pathway Control of Amino Acid Biosynthesis Is Required for Pathogenicity of the Vascular Pathogen Verticillium longisporum

2013 ◽  
Vol 26 (11) ◽  
pp. 1312-1324 ◽  
Author(s):  
Christian Timpner ◽  
Susanna A. Braus-Stromeyer ◽  
Van Tuan Tran ◽  
Gerhard H. Braus
Keyword(s):  
Amino Acid ◽  
Oilseed Rape ◽  
Host Plants ◽  
Pathogenic Fungus ◽  
Amino Acid Biosynthesis ◽  
Amino Acid Starvation ◽  
Acid Biosynthesis ◽  
Plant Host ◽  
Verticillium Longisporum ◽  
The Cross

The plant-pathogenic fungus Verticillium longisporum is a causal agent of early senescence and ripening in cruciferous crops like Brassica napus. Verticillium wilts have become serious agricultural threats in recent decades. Verticillium species infect host plants through the roots and colonize xylem vessels of the host plant. The xylem fluid provides an environment with limited carbon sources and unbalanced amino acid supply, which requires V. longisporum to induce the cross-pathway control of amino acid biosynthesis. RNA-mediated gene silencing reduced the expression of the two CPC1 isogenes (VlCPC1-1 and VlCPC1-2) of the allodiploid V. longisporum up to 85%. VlCPC1 encodes the conserved transcription factor of the cross-pathway control. The silenced mutants were highly sensitive to amino-acid starvation, and the infected plants showed significantly fewer symptoms such as stunting or early senescence in oilseed rape plant infection assays. Consistently, deletion of single CPC1 of the haploid V. dahliae resulted in strains that are sensitive to amino-acid starvation and cause strongly reduced symptoms in the plant-host tomato (Solanum lycopersicum). The allodiploid V. longisporum and the haploid V. dahliae are the first phytopathogenic fungi that were shown to require CPC1 for infection and colonization of their respective host plants, oilseed rape and tomato.

scholarly journals Involvement of Salicylic Acid in the Establishment of the Rhizobium meliloti-Alfalfa Symbiosis

1998 ◽  
Vol 11 (2) ◽  
pp. 153-155 ◽  
Author(s):  
F. Martínez-Abarca ◽  
J. A. Herrera-Cervera ◽  
P. Bueno ◽  
J. Sanjuan ◽  
T. Bisseling ◽  
...  
Keyword(s):  
Salicylic Acid ◽  
Rhizobium Meliloti ◽  
Significant Inhibition ◽  
Nod Factors ◽  
Wild Type ◽  
Nod Factor ◽  
Rhizobium Strains ◽  
Meliloti Strain

Inoculation of alfalfa plants with either incompatible Rhizobium or a Rhizobium mutant blocked in Nod factor synthesis led to an accumulation of salicylic acid in roots, in contrast to plants inoculated with a wild-type (compatible) R. meliloti strain. When salicylic acid was exogenously applied prior to inoculation of alfalfa plants with either purified Nod factor or compatible Rhizobium strains, a significant inhibition of nodule primordia formation and a reduction of the number of emerging nodules, respectively, as well as a delay in nodule visualization, were observed. These results suggest an involvement of Rhizobium-synthesized Nod factors in the inhibition of salicylic acid-mediated defense in legumes.

Kinetic properties of ATP sulfurylase and APS kinase from Thiobacillus denitrificans

2009 ◽  
Vol 489 (1-2) ◽  
pp. 110-117 ◽  
Author(s):  
Sean C. Gay ◽  
Jennifer L. Fribourgh ◽  
Paul D. Donohoue ◽  
Irwin H. Segel ◽  
Andrew J. Fisher
Keyword(s):  
Kinetic Properties ◽  
Thiobacillus Denitrificans ◽  
Atp Sulfurylase ◽  
Aps Kinase

scholarly journals Import of Entamoeba histolytica Mitosomal ATP Sulfurylase Relies on Internal Targeting Sequences

2020 ◽  
Vol 8 (8) ◽  
pp. 1229
Author(s):  
Herbert J. Santos ◽  
Yoko Chiba ◽  
Takashi Makiuchi ◽  
Saki Arakawa ◽  
Yoshitaka Murakami ◽  
...  
Keyword(s):  
Entamoeba Histolytica ◽  
Intestinal Parasite ◽  
Subcellular Fractionation ◽  
Immunofluorescence Assay ◽  
Matrix Proteins ◽  
Desulfovibrio Vulgaris ◽  
Chimeric Proteins ◽  
Atp Sulfurylase ◽  
Sulfate Activation

Mitochondrial matrix proteins synthesized in the cytosol often contain amino (N)-terminal targeting sequences (NTSs), or alternately internal targeting sequences (ITSs), which enable them to be properly translocated to the organelle. Such sequences are also required for proteins targeted to mitochondrion-related organelles (MROs) that are present in a few species of anaerobic eukaryotes. Similar to other MROs, the mitosomes of the human intestinal parasite Entamoeba histolytica are highly degenerate, because a majority of the components involved in various processes occurring in the canonical mitochondria are either missing or modified. As of yet, sulfate activation continues to be the only identified role of the relic mitochondria of Entamoeba. Mitosomes influence the parasitic nature of E. histolytica, as the downstream cytosolic products of sulfate activation have been reported to be essential in proliferation and encystation. Here, we investigated the position of the targeting sequence of one of the mitosomal matrix enzymes involved in the sulfate activation pathway, ATP sulfurylase (AS). We confirmed by immunofluorescence assay and subcellular fractionation that hemagluttinin (HA)-tagged EhAS was targeted to mitosomes. However, its ortholog in the δ-proteobacterium Desulfovibrio vulgaris, expressed as DvAS-HA in amoebic trophozoites, indicated cytosolic localization, suggesting a lack of recognizable mitosome targeting sequence in this protein. By expressing chimeric proteins containing swapped sequences between EhAS and DvAS in amoebic cells, we identified the ITSs responsible for mitosome targeting of EhAS. This observation is similar to other parasitic protozoans that harbor MROs, suggesting a convergent feature among various MROs in favoring ITS for the recognition and translocation of targeted proteins.

scholarly journals Description of new species of leaf miners (Diptera Agromyzidae) associated with leguminous host described from northern India

2013 ◽  
Vol 1 ◽  
pp. 66-82 ◽  
Author(s):  
Ram Bahadur Thapa
Keyword(s):  
New Species ◽  
Vicia Faba ◽  
Host Plants ◽  
Trifolium Pratense ◽  
Vigna Mungo ◽  
Pueraria Phaseoloides ◽  
Leaf Miners ◽  
New Host ◽  
Northern India ◽  
Leguminous Host

A total of 28 species of agromyzid flies belonging to 7 genera have been reared and described on 34 different leguminous host -plants from Pantnagar, Nainital, Northern India. 13 agromyzid flies have been described as new species viz., Japanagromyza species nova (sp.n.) ex leaves of Pueraria phaseoloides (Roxb.) Benth; Liriomyza sp.n. ex leaves of Vicia sativa Linn.; Liriomyza sp.n. ex leaves of Vicia faba Linn.; Malanagromyza sp.n. ex stems of Cassia sp.; Melanagromyza sp.n. ex stems of Pisum sativum Linn. Melanagromyza sp.n. ex stems of Trifolium pratense Linn.; Melanagromyza sp.n. ex stems of Vicia faba Linn.; Ophiomyia sp.n. ex stems of Pueraria Phaseoloides (Roxb.) Benth; Ophiomyia sp.n. ex stems of Sesbania aculeata Pers.; Ophiomyiz sp.n. ex stem of Vigna mungo (Linn.) Heeper and Ophiomyia sp.n. ex stems of Vigna mungo (Linn.) Heeper. Large numbers of host plants have been recorded as new host for various agromyzid species. More than one thousand male genitalia slides have been prepared for this study. Variations in morphology and genitalia characters have also been illustrated within the species. DOI: http://dx.doi.org/10.3126/njbs.v1i0.7474 Nepalese Journal of Biosciences 1: 66-82 (2011)

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