Molecular cloning and characterization of the recA gene of Methylomonas clara and construction of recA deficient mutant

Ridder, Rüdiger; Marquardt, Rüdiger; Esser, Karl

doi:10.1007/bf00180631

Cited by 8 publications

(1 citation statement)

References 46 publications

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“…This response to DNA damage is probably widespread in bacteria, and SOS genes other than those in E. coli have been identified; these genes contain LexA-binding sequences in their promoter regions. Not all cloned recA genes have identifiable LexA binding sites (9,11,19,23,24,45,52,53,63,72), and it is not known whether this represents a different form of regulation of recA in those bacteria. The lack of a consensus LexA binding site in the H. pylori recA promoter may have implications regarding the regulation of a putative SOS-like response in H. pylori.…”

Section: Discussionmentioning

confidence: 99%

Isolation of the Helicobacter pylori recA gene and involvement of the recA region in resistance to low pH

1995

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To understand the potential roles of the important DNA repair protein RecA in Helicobacter pylori pathogenesis, we cloned the recA gene from H. pylori 84-183. Degenerate PCR primers based on conserved RecA protein regions were used to amplify a portion of H. pylori recA, which was used as a probe to isolate the full-length recA gene from H. pylori genomic libraries. The H. pylori recA gene encoded a protein of 347 amino acids with a molecular mass of 37.6 kDa. As expected, H. pylori RecA was highly similar to other RecA proteins and most closely resembled that of Campylobacter jejuni (75% identity). Immediately downstream of recA was an open reading frame whose predicted product showed 58% identity to the Bacillus subtilis enolase protein. recA and eno were disrupted in H. pylori 84-183 by insertion of antibiotic resistance genes. Reverse transcription-PCR demonstrated that recA and eno were cotranscribed and that insertion of the kanamycin resistance gene into recA had polar effects on expression of the downstream eno. The H. pylori recA mutants were severely impaired in their ability to survive treatment with UV light and methyl methanesulfonate and with the antimicrobial agents ciprofloxacin and metronidazole. The eno mutant had sensitivities to UV light and metronidazole intermediate to those of wild-type and recA strains, suggesting that truncation of the recA-eno transcript resulted in lowered recA expression. For survival at low pH, a recA mutant was approximately 10-fold more sensitive than strain 84-183, while the eno mutant demonstrated intermediate susceptibility. This difference occurred in the presence or absence of urea, implying the involvement of a gene in the recA region in an acid resistance mechanism distinct from that mediated by urease.

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Section: Discussionmentioning

confidence: 99%

Isolation of the Helicobacter pylori recA gene and involvement of the recA region in resistance to low pH

1995

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The RecA protein as a model molecule for molecular systematic studies of bacteria: Comparison of trees of RecAs and 16S rRNAs from the same species

1995

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The evolution of the RecA protein was analyzed using molecular phylogenetic techniques. Phylogenetic trees of all currently available complete RecA proteins were inferred using multiple maximum parsimony and distance matrix methods. Comparison and analysis of the trees reveal that the inferred relationships among these proteins are highly robust. The RecA trees show consistent subdivisions corresponding to many of the major bacterial groups found in trees of other molecules including the α, β, γ, δ, and ε Proteobacteria, cyanobacteria, high-GC grampositives, and the Deinococcus-Thermus group. However, there are interesting differences between the RecA trees and these other trees. For example, in all the RecA trees the proteins from gram-positives species are not monophyletic. In addition, the RecAs of the cyanobacteria consistently group with the RecAs of the high-GC gram-positives. To evaluate possible causes and implications of these and other differences, phylogenetic trees were generated for small-subunit rRNA sequences from the same (or closely related) species as represented in the RecA analysis. The trees of the two molecules using these equivalent species-sets are highly congruent and have similar resolving power for close, medium, and deep branches in the history of bacteria. The implications of the particular similarities and differences between the trees are discussed. Some of the features that make RecA useful for molecular systematics and for studies of protein evolution are also discussed.

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Interspecies regulation of the recA gene of gram-negative bacteria lacking an E. coli-like SOS operator

Riera

Garriga

et al. 1994

Molec. Gen. Genet.

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The recA genes of Agrobacterium tumefaciens, Rhizobium meliloti, Rhizobium phaseoli and Rhodobacter sphaeroides, species belonging to the alpha-group bacteria of the Proteobacteria class, have been fused in vitro to the lacZ gene of Escherichia coli. By using a mini-Tn5 transposon derivative, each of these recA-lacZ fusions was introduced into the chromosome of each of the four species, and into that of E. coli. The recA genes of three of the alpha bacteria are induced by DNA damage when inserted in A. tumefaciens, R. phaseoli or R. meliloti chromosomes. The expression of the recA gene of R. sphaeroides is DNA damage-mediated only when present in its own chromosome; none of the genes is induced in E. coli. Likewise, the recA gene of E. coli is not induced in any of the four alpha species. These data indicate that A. tumefaciens, R. meliloti and R. phaseoli possess a LexA-like repressor, which is able to block the expression of their recA genes, as well as that of R. sphaeroides, but not the recA gene of E. coli. The LexA repressor of R. sphaeroides does not repress the recA gene of A. tumefaciens, R. meliloti, R. phaseoli or E. coli.

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Molecular cloning and characterization of the recA gene of Methylomonas clara and construction of recA deficient mutant

Cited by 8 publications

References 46 publications

Isolation of the Helicobacter pylori recA gene and involvement of the recA region in resistance to low pH

Isolation of the Helicobacter pylori recA gene and involvement of the recA region in resistance to low pH

The RecA protein as a model molecule for molecular systematic studies of bacteria: Comparison of trees of RecAs and 16S rRNAs from the same species

Interspecies regulation of the recA gene of gram-negative bacteria lacking an E. coli-like SOS operator

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