Molecular Characterization and Expression of the recX Gene of Xanthomonas campestris pv. citri

Yang, Ming‐Der; Chou, Min-En; Yang, Yen-Chun

doi:10.1007/s002840110214

Cited by 19 publications

(24 citation statements)

References 17 publications

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“…In Xanthomonas campestris pv. citri, recA and recX are thought to be transcribed from their own promoters but expression of both is induced by DNA damage (53). Thus, despite the prediction that recA and oraA constitute independent transcriptional units in E. coli (39), it is likely that the LexA-regulated recA promoter present in the oraA-luxCDABE gene fusion plasmid (Table 1) controls transcription of oraA.…”

Section: Vol 183 2001 E Coli Cellular Arrays For Transcription Anamentioning

confidence: 98%

LuxArray, a High-Density, Genomewide Transcription Analysis of Escherichia coli Using Bioluminescent Reporter Strains

2001

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A sequenced collection of plasmid-borne random fusions of Escherichia coli DNA to a Photorhabdus luminescens luxCDABE reporter was used as a starting point to select a set of 689 nonredundant functional gene fusions. This group, called LuxArray 1.0, represented 27% of the predicted transcriptional units in E. coli. High-density printing of the LuxArray 1.0 reporter strains to membranes on agar plates was used for simultaneous reporter gene assays of gene expression. The cellular response to nalidixic acid perturbation was analyzed using this format. As expected, fusions to promoters of LexA-controlled SOS-responsive genes dinG, dinB, uvrA, and ydjM were found to be upregulated in the presence of nalidixic acid. In addition, six fusions to genes not previously known to be induced by nalidixic acid were also reproducibly upregulated. The responses of two of these, fusions to oraA and yigN, were induced in a LexA-dependent manner by both nalidixic acid and mitomycin C, identifying these as members of the LexA regulon. The responses of the other four were neither induced by mitomycin C nor dependent on lexA function. Thus, the promoters of ycgH, intG, rihC, and a putative operon consisting of lpxA, lpxB, rnhB, and dnaE were not generally DNA damage responsive and represent a more specific response to nalidixic acid. These results demonstrate that cellular arrays of reporter gene fusions are an important alternative to DNA arrays for genomewide transcriptional analyses.

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Section: Vol 183 2001 E Coli Cellular Arrays For Transcription Anamentioning

confidence: 98%

LuxArray, a High-Density, Genomewide Transcription Analysis of Escherichia coli Using Bioluminescent Reporter Strains

2001

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“…A gene designated recX has been identified downstream of recA in many organisms, and in some instances the coding regions for the recA and recX genes overlap (De Mot et al, 1994 ;Yang et al, 2001). In mycobacteria and Streptomyces lividans the genes are cotranscribed (Papavinasasundaram et al, 1997 ;Vierling et al, 2000).…”

Section: Abbreviation : Gc Neisseria Gonorrhoeaementioning

confidence: 99%

Differential cross-complementation patterns of Escherichia coli and Neisseria gonorrhoeae RecA proteins

2002

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The Escherichia coli RecA protein is one of the best-studied enzymes, but less is understood about how RecA homologues of other species are similar to or different from the E. coli RecA. In the Gram-negative pathogen Neisseria gonorrhoeae (the gonococcus ; Gc), the causative agent of gonorrhoea, RecA is involved in DNA transformation, pilin antigenic variation, and DNA repair. By expressing the recA genes from Gc and E. coli under control of lac regulatory sequences in E. coli, the authors have shown that the Gc RecA fully complements an E. coli recA mutant for homologous recombination, but only partially complements for survival to DNA damage. By expressing similar constructs in Gc, it was shown that the E. coli RecA complements for pilin antigenic variation, partially complements for DNA transformation, but does not complement for survival to DNA damage, suggesting that species-specific interactions are important for DNA repair, but not for homologous recombination. Co-expression of the E. coli recA and recX genes in Gc suggests that in this heterologous system RecX modulates RecA-mediated processes.

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“…formed by using DNA probes labeled with digoxigenin (DIG) or 32 P by random priming. The sensitivity of X. axonopodis pv.…”

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confidence: 99%

Identification and Characterization of a SecondlexAGene ofXanthomonas axonopodisPathovar citri

Yang

Sung

2005

Appl Environ Microbiol

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We previously identified and characterized a lexA gene from Xanthomonas axonopodis pv. citri. For this study, we cloned and expressed a lexA homologue from X. axonopodis pv. citri. This gene was designated lexA2, and the previously identified lexA gene was renamed lexA1. The coding region of lexA2 is 606 bp long and shares 59% nucleotide sequence identity with lexA1. Analyses of the deduced amino acid sequence revealed that LexA2 has structures that are characteristic of LexA proteins, including a helix-turn-helix DNA binding domain and conserved amino acid residues required for the autocleavage of LexA. The lexA2 mutant, which was constructed by gene replacement, was 4 orders of magnitude more resistant to the DNA-damaging agent mitomycin C at 0.1 g/ml and 1 order of magnitude more resistant to another DNA-damaging agent, methylmethane sulfonate at 30 g/ml, than the wild type. A lexA1 lexA2 double mutant had the same degree of susceptibility to mitomycin C as the lexA1 or lexA2 single mutant but was 1 order of magnitude more resistant to methylmethane sulfonate at 30 g/ml than the lexA1 or lexA2 single mutant. These results suggest that LexA1 and LexA2 play different roles in regulating the production of methyltransferases that are required for repairing DNA damage caused by methylmethane sulfonate. A mitomycin C treatment also caused LexA2 to undergo autocleavage, as seen with LexA1. The results of electrophoresis mobility shift assays revealed that LexA2 does not bind the lexA1 promoter. It binds to both the lexA2 and recA promoters. However, neither LexA2 nor LexA1 appears to regulate recA expression, as lexA1, lexA2, and lexA1 lexA2 mutants did not become constitutive for recA transcription and RecA production. These results suggest that recA expression in X. axonopodis pv. citri is regulated by mechanisms that have yet to be identified.

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Molecular Characterization and Expression of the recX Gene of Xanthomonas campestris pv. citri

Cited by 19 publications

References 17 publications

LuxArray, a High-Density, Genomewide Transcription Analysis of Escherichia coli Using Bioluminescent Reporter Strains

LuxArray, a High-Density, Genomewide Transcription Analysis of Escherichia coli Using Bioluminescent Reporter Strains

Differential cross-complementation patterns of Escherichia coli and Neisseria gonorrhoeae RecA proteins

Identification and Characterization of a SecondlexAGene ofXanthomonas axonopodisPathovar citri

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