Regulation of expression and nucleotide sequence of the Anabaena variabilis recA gene

Owttrim, George W.; Coleman, John R.

doi:10.1128/jb.171.10.5713-5719.1989

Cited by 38 publications

(11 citation statements)

References 24 publications

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“…Thus, there may be inducible expression through the regulation of a LexA-like protein with a recognition sequence different from that of its E. coli counterpart. The Anabaena variabilis recA gene has no E. coli-like SOS box, but its expression is UV-, mitomycin C-, and MMS-inducible in A. variabilis itself (45). In contrast, in Thiobacillus ferrooxidans, the recA gene has no SOS box and is not inducible (46).…”

Section: Resultsmentioning

confidence: 93%

Novel structure of the recA locus of Mycobacterium tuberculosis implies processing of the gene product

1991

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A fragment of Mycobacterium tuberculosis DNA containing recA-like sequences was identified by hybridization with the Escherichia coli recA gene and cloned. Although no expression was detected from its own promoter in E. coli, expression from a vector promoter partially complemented E. coli recA mutants for recombination, DNA repair, and mutagenesis, but not for induction of phage K. This clone produced a protein which cross-reacts with antisera raised against the E. coli RecA protein and was approximately the same size. However, the nucleotide sequence of the cloned fragment revealed the presence of an open reading frame for a protein about twice the size of other RecA proteins and the cloned product detected by Western blotting (immunoblotting). The predicted M. tuberculosis RecA protein sequence was homologous with RecA sequences from other bacteria, but this homology was not dispersed; rather it was localized to the first 254 and the last 96 amino acids, with the intervening 440 amino acids being unrelated. Furthermore, the junctions of homology were in register with the uninterrupted sequence Qf the E. coli RecA protein. Identical restriction fragments were found in the genomic DNAs of M. tuberculosis H37Rv and H37Ra and of M. bovis BCG. It is concluded that the ancestral recA gene of these species diversified via an insertional mutation of at least 1,320 bp of DNA. Possible processing mechanisms for synthesizing a normal-size RecA protein from this elongated sequence are discussed.

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Section: Resultsmentioning

confidence: 93%

Novel structure of the recA locus of Mycobacterium tuberculosis implies processing of the gene product

1991

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“…Cloning of the H. pylori recA gene by PCR The protein sequences located at positions 64-70 and 245-251 of the E. coli RecA protein proved to be strongly conserved between the eleven RecA sequences of different bacterial species which were compared (Sancar et al 1980;Sano and Kageyama 1987;Akaboshi et al 1989;Owttrim and Coleman 1989;Ramesar et al 1989;Ball et al 1990;Berson et al 1990;Favre and Viret 1990;Fyfe and Davies 1990;Goodman and Woods 1990;Michiels et al 1991). Two degenerate PCR primers, WS001 and WS002, were designed on the basis of the RecA protein sequences EIYGPES and VKVVKNK, respectively.…”

Section: Resultsmentioning

confidence: 99%

Cloning of theHelicobacter pylori recA gene and functional characterization of its product

et al. 1995

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The RecA protein is a key enzyme involved in DNA recombination in bacteria. Using a polymerase chain reaction (PCR) amplification we cloned a recA homolog from Helicobacter pylori. The gene revealed an open reading frame (ORF) encoding a putative protein of 37.6 kDa showing closest homology to the Campylobacter jejuni RecA (75.5% identity). A putative ribosome binding site and a near-consensus sigma 70 promoter sequence was found upstream of recA. A second ORF, encoding a putative protein with N-terminal sequence homology to prokaryotic and eukaryotic enolases, is located directly downstream of recA. Compared to the wild-type strains, isogenic H. pylori recA deletion mutants of strains 69A and NCTC11637 displayed increased sensitivity to ultraviolet light and abolished general homologous recombination. The recombinant H. pylori RecA protein produced in Escherichia coli strain GC6 (recA-) was 38 kDa in size but inactive in DNA repair, whereas the corresponding protein in H. pylori 69A migrated at the greater apparent molecular weight of approx. 40 kDa in SDS-polyacrylamide gels. However, complementation of the H. pylori mutant using the cloned recA gene on a shuttle vector resulted in a RecA protein of the original size and fully restored the general functions of the enzyme. These data can be best explained by a modification of RecA in H. pylori which is crucial for its function. The potential modification seems not to occur when the protein is produced in E. coli, giving rise to a smaller but inactive protein.

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“…In several cyanobacterial strains, sensitivity to UV irradiation increases in the presence of caffeine or acriflavine (an inhibitor of excision repair), providing indirect evidence of excision repair in cyanobacteria [160]. Moreover, an increase in the transcript levels of recA and a concomitant increase in the abundance of the corresponding 37-38-kDa polypeptide have been reported in A. variabilis following UV irradiation [159]. The recA gene encodes a DNA-dependent ATPase that binds to single-stranded DNA and promotes strand invasion and exchange between homologous DNA molecules [160].…”

Section: Repair and Resynthesis Of Damaged Dna And Proteins In Cyanobmentioning

confidence: 95%

Ultraviolet radiation and cyanobacteria

Rastogi

Sinha

Moh³

et al. 2014

Journal of Photochemistry and Photobiology B: Biology

165

109

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Cyanobacteria are the dominant photosynthetic prokaryotes from an ecological, economical, or evolutionary perspective, and depend on solar energy to conduct their normal life processes. However, the marked increase in solar ultraviolet radiation (UVR) caused by the continuous depletion of the stratospheric ozone shield has fueled serious concerns about the ecological consequences for all living organisms, including cyanobacteria. UV-B radiation can damage cellular DNA and several physiological and biochemical processes in cyanobacterial cells, either directly, through its interaction with certain biomolecules that absorb in the UV range, or indirectly, with the oxidative stress exerted by reactive oxygen species. However, cyanobacteria have a long history of survival on Earth, and they predate the existence of the present ozone shield. To withstand the detrimental effects of solar UVR, these prokaryotes have evolved several lines of defense and various tolerance mechanisms, including avoidance, antioxidant production, DNA repair, protein resynthesis, programmed cell death, and the synthesis of UV-absorbing/screening compounds, such as mycosporine-like amino acids (MAAs) and scytonemin. This study critically reviews the current information on the effects of UVR on several physiological and biochemical processes of cyanobacteria and the various tolerance mechanisms they have developed. Genomic insights into the biosynthesis of MAAs and scytonemin and recent advances in our understanding of the roles of exopolysaccharides and heat shock proteins in photoprotection are also discussed.

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Regulation of expression and nucleotide sequence of the Anabaena variabilis recA gene

Cited by 38 publications

References 24 publications

Novel structure of the recA locus of Mycobacterium tuberculosis implies processing of the gene product

Novel structure of the recA locus of Mycobacterium tuberculosis implies processing of the gene product

Cloning of theHelicobacter pylori recA gene and functional characterization of its product

Ultraviolet radiation and cyanobacteria

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