In Rhizobium etli Symbiotic Plasmid Transfer, Nodulation Competitivity and Cellular Growth Require Interaction among Different Replicons

Plasmid ◽  
2000 ◽  
Vol 44 (1) ◽  
pp. 34-43 ◽  
Author(s):  
Susana Brom ◽  
Alejandro Garcı́a-de los Santos ◽  
Laura Cervantes ◽  
Rafael Palacios ◽  
David Romero
Keyword(s):  
Plasmid Transfer ◽  
Cellular Growth ◽  
Rhizobium Etli ◽  
Symbiotic Plasmid

The Symbiotic Plasmid of Rhizobium Etli

1999 ◽  
pp. 163-165 ◽  
Author(s):  
J. G. Dávila ◽  
P. Bustos ◽  
M. A. Cevallos ◽  
M. L. Girard ◽  
R. Palacios ◽  
...  
Keyword(s):  
Rhizobium Etli ◽  
Symbiotic Plasmid

Plasmid replicons of Rhizobium

2005 ◽  
Vol 33 (1) ◽  
pp. 157-158 ◽  
Author(s):  
L.C. Crossman
Keyword(s):  
Short Review ◽  
Nitrogen Fixing ◽  
Rhizobium Etli ◽  
Free Living ◽  
Leguminous Plants ◽  
Symbiotic Plasmid ◽  
Rhizobium Spp ◽  
Plasmid Replicons ◽  
Rhizobium Sp

Rhizobium spp. are found in soil. They are both free-living and found symbiotically associated with the nodules of leguminous plants. Traditionally, studies have focused on the association of these organisms with plants in nitrogen-fixing nodules, since this is regarded as the most important role of these bacteria in the environment. Rhizobium sp. are known to possess several replicons. Some, like the Rhizobium etli symbiotic plasmid p42d and the plasmid pNGR234b of Rhizobium NGR234, have been sequenced and characterized. The plasmids from these organisms are the focus of this short review.

A site-specific recombinase (RinQ) is required to exert incompatibility towards the symbiotic plasmid of Rhizobium etli

2002 ◽  
Vol 46 (4) ◽  
pp. 1023-1032 ◽  
Author(s):  
Verónica Quintero ◽  
Miguel A. Cevallos ◽  
Guillermo Dávila
Keyword(s):  
Rhizobium Etli ◽  
Site Specific ◽  
Symbiotic Plasmid ◽  
A Site

scholarly journals Differential Regulation of fixN-Reiterated Genes in Rhizobium etli by a Novel fixL—fixK Cascade

2000 ◽  
Vol 13 (12) ◽  
pp. 1283-1292 ◽  
Author(s):  
Lourdes Girard ◽  
Susana Brom ◽  
Araceli Dávalos ◽  
Oswaldo López ◽  
Mario Soberón ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Regulatory Element ◽  
Regulatory Gene ◽  
Regulatory System ◽  
Differential Regulation ◽  
Rhizobium Etli ◽  
Free Living ◽  
Symbiotic Plasmid ◽  
Independent Mechanism ◽  
Fusion Analysis

Among the complexities in the regulation of nitrogen fixation in the Rhizobiaceae are reiteration of regulatory components as well as variant roles for each component between species. For Rhizobium etli CFN42, we reported that the symbiotic plasmid (pCFN42d) contains a key regulatory gene (fixKd) and genes for a symbiotic cytochrome oxidase (fixNOQPd). Here we discuss the occurrence of reiteration of these genes (fixKf and fixNOQPf) and the finding of an unusual fixL homolog on a plasmid previously considered cryptic (pCFN42f). The structure of the deduced FixL polypeptide is suggestive of a fusion of the receiver and transmitter modules of a two-component regulatory system as described in R. leguminosarum bv. viciae VF39. Gene fusion analysis, coupled with mutation of each regulatory element, revealed that free-living expression of FixKf was dependent fully on FixL. In contrast, synthesis of FixKd was not detected under the conditions tested. The FixKf protein is needed for microaerobic expression of both fixN reiterations, whereas the FixKd protein appears to be dispensable. Interestingly, expression of the fixN reiterations exhibits a differential dependence for FixL, where transcription of fixNf was suppressed in the absence of FixL but expression of fixNd still showed significant levels. This suggests the existence of a FixL-independent mechanism for expression of the fixNd reiteration. Surprisingly, mutations in fixL, fixKd, or fixKf (either singly or in combination) did not alter symbiotic effectiveness. A mutation in fixNd (but not in fixNf) was, however, severely affected, indicating a differential role for these reiterations in nitrogen fixation.

scholarly journals The Relaxase of the Rhizobium etli Symbiotic Plasmid Shows nic Site cis-Acting Preference

2006 ◽  
Vol 188 (21) ◽  
pp. 7488-7499 ◽  
Author(s):  
Daniel Pérez-Mendoza ◽  
María Lucas ◽  
Socorro Muñoz ◽  
José A. Herrera-Cervera ◽  
José Olivares ◽  
...  
Keyword(s):  
Biochemical Characterization ◽  
Rhizobium Etli ◽  
Cis Acting ◽  
Cleavage Activity ◽  
Symbiotic Plasmid ◽  
The Family ◽  
Nick Site ◽  
First Time

ABSTRACT Genetic and biochemical characterization of TraA, the relaxase of symbiotic plasmid pRetCFN42d from Rhizobium etli, is described. After purifying the relaxase domain (N265TraA), we demonstrated nic binding and cleavage activity in vitro and thus characterized for the first time the nick site (nic) of a plasmid in the family Rhizobiaceae. We studied the range of N265TraA relaxase specificity in vitro by testing different oligonucleotides in binding and nicking assays. In addition, the ability of pRetCFN42d to mobilize different Rhizobiaceae plasmid origins of transfer (oriT) was examined. Data obtained with these approaches allowed us to establish functional and phylogenetic relationships between different plasmids of this family. Our results suggest novel characteristics of the R. etli pSym relaxase for previously described conjugative systems, with emphasis on the oriT cis-acting preference of this enzyme and its possible biological relevance.

scholarly journals Analysis of the Mechanism of Action of the Antisense RNA That Controls the Replication of the repABC Plasmid p42d

2010 ◽  
Vol 192 (13) ◽  
pp. 3268-3278 ◽  
Author(s):  
Ramón Cervantes-Rivera ◽  
Cristina Romero-López ◽  
Alfredo Berzal-Herranz ◽  
Miguel A. Cevallos
Keyword(s):  
Mechanism Of Action ◽  
Antisense Rna ◽  
Effective Interaction ◽  
Plasmid Replication ◽  
Rhizobium Etli ◽  
Antisense Molecule ◽  
Initiator Protein ◽  
Symbiotic Plasmid ◽  
Protein Encoding ◽  
Encoding Genes

ABSTRACT Replication and segregation of the Rhizobium etli symbiotic plasmid (pRetCFN42d) depend on the presence of a repABC operon, which carries all the plasmid-encoded elements required for these functions. All repABC operons share three protein-encoding genes (repA, repB, and repC), an antisense RNA (ctRNA) coding gene, and at least one centromere-like region (parS). The products of repA and repB, in conjunction with the parS region, make up the segregation system, and they negatively regulate operon transcription. The last gene of the operon, repC, encodes the initiator protein. The ctRNA is a negative posttranscriptional regulator of repC. In this work, we analyzed the secondary structures of the ctRNA and its target and mapped the motifs involved in the complex formed between them. Essential residues for the effective interaction localize at the unpaired 5′ end of the antisense molecule and the loop of the target mRNA. In light of our results, we propose a model explaining the mechanism of action of this ctRNA in the regulation of plasmid replication in R. etli.

scholarly journals Sequence, localization and characteristics of the replicator region of the symbiotic plasmid of Rhizobium etli

Microbiology ◽  
1997 ◽  
Vol 143 (8) ◽  
pp. 2825-2831 ◽  
Author(s):  
M. A. Ramirez-Romero ◽  
P. Bustos ◽  
L. Girard ◽  
O. Rodriguez ◽  
M. A. Cevallos ◽  
...  
Keyword(s):  
Rhizobium Etli ◽  
Symbiotic Plasmid

Incompatibility and the partitioning site of the repABC basic replicon of the symbiotic plasmid from Rhizobium etli

Plasmid ◽  
2004 ◽  
Vol 51 (3) ◽  
pp. 203-216 ◽  
Author(s):  
Nora Soberón ◽  
Tatiana Venkova-Canova ◽  
Miguel A. Ramı́rez-Romero ◽  
Juan Téllez-Sosa ◽  
Miguel A. Cevallos
Keyword(s):  
Rhizobium Etli ◽  
Symbiotic Plasmid

RepA negatively autoregulates the transcription of the repABC operon of the Rhizobium etli symbiotic plasmid basic replicon

2008 ◽  
Vol 42 (1) ◽  
pp. 195-204 ◽  
Author(s):  
Miguel A. Ramírez-Romero ◽  
Juan Téllez-Sosa ◽  
Humberto Barrios ◽  
Angeles Pérez-Oseguera ◽  
Vania Rosas ◽  
...  
Keyword(s):  
Rhizobium Etli ◽  
Symbiotic Plasmid
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