Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:Q9UIJ5 (Rec)
 58,342 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Plasmids containing sequences 3' of the adult beta 1 globin gene of Xenopus laevis are unstable on propagation in a range of E. coli host strains. Up to 300 bp of Xenopus DNA are lost by rec A independent recombination between (AT)37 and (AT)17 sequences. Additionally, smaller deletions occurring in or around the (AT)37 sequence are observed. Deletion of these potential cruciform structures occurs in the absence of exonuclease I, exonuclease V and exonuclease VIII as the same pattern of deletion events is observed in recA recBC sbcB and recBC sbcA recE strains.
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PMID:RecBC, sbcB independent, (AT)n-mediated deletion of sequences flanking a Xenopus laevis beta globin gene on propagation in E. coli. 301 63

Shutoff of respiration is one of a number of recA+ lexA+ dependent (SOS) responses caused by far ultraviolet (245 nm) radiation (UV) damage of DNA in Escherichia coli cells. Thus far no rec/lex response has been shown to require the recB recC gene product, the RecBC enzyme. We report in this paper that UV-induced respiration shutoff did not occur in either of these radiation-sensitive derivatives of K12 strain AB1157 nor in the recB recC double mutant. The sbcB gene product is exonuclease I and it has been reported that the triple mutant strain recB recC sbcB has near normal recombination efficiency and resistance to UV. The sbcB strain shut off its respiration after UV but the triple mutant did not show UV-induced respiration shutoff; the shutoff and death responses were uncoupled. We concluded that respiration shutoff requires RecBC enzyme activity. The RecBC enzyme has ATP-dependent double-strand exonuclease activity, helicase activity and several other activities. We tested a recBC+ (double dagger) mutant strain (recC 1010) that had normal recombination efficiency and resistance to UV but which possessed no ATP-dependent double-strand exonuclease activity. This strain did not shut off its respiration. The presence or absence of other RecBC enzyme activities in this mutant is not known. These results support the hypothesis that ATP-dependent double-strand exonuclease activity is necessary for UV-induced respiration shutoff.
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PMID:RecBC enzyme activity is required for far-UV induced respiration shutoff in Escherichia coli K12. 351 Mar 70

The role of inducible cell functions in repair and mutagenesis after bleomycin-induced DNA damages was studied in Escherichia coli. Influence on these processes of some rec genes as well as sbcB, the structural gene for exonuclease I, was investigated. The data obtained suggest that this enzyme plays a negative role in the repair of DNA damaged by bleomycin. The hypersensitivity of recA mutant to bleomycin and recAlexA-dependence of bleomycin-induced mutagenesis do not suggest any principal differences between UV-induced pyrimidine dimers and apyrimidinic sites in the case of post-replication repair.
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PMID:[Repair of bleomycin-induced damage to Escherichia coli DNA. II. Participation of inducible processes]. 616 59

The recombination proficiency of three recipient strains of Escherichia coli K12 carrying different plasmids was investigated by conjugal mating with Hfr Cavalli. Some plasmids (e.g. R1drd 19, R6K) caused a marked reduction in the yield of recombinants formed in crosses with Hfr but did not reduce the ability of host strains to accept plasmid F104. The effect of plasmids on recombination was host-dependent. In Hfr crosses with AB1157 (R1-19) used as a recipient the linkage between selected and unselected proximal markers of the donor was sharply decreased. Plasmid R1-19 also decreased the yield of recombinants formed by recF, recL, and recB recC sbcA mutants, showed no effect on the recombination proficiency of recB recC sbcB mutant, and increased the recombination proficiency of recB, recB recC sbcB recF, and recB recC sbcB recL mutants. An ATP-dependent exonuclease activity was found in all tested recB recC mutants carrying plasmid R1-19, while this plasmid did not affect the activity of exonuclease I in strain AB1157 and its rec- derivatives. The same plasmid was also found to protect different rec- derivatives of the strain AB1157 against the lethal action of UV light. We suppose that a new ATP-dependent exonuclease determined by R1-19 plays a role in both repair and recombination of the host through the substitution of or competition with the exoV coded for by the genes recB and recC.
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PMID:Plasmid control of recombination of E. coli K12. 625 17

When Escherichia coli K12(lambda) lysogens are infected with heteroimmune lambda phage, which are unable to replicate, general recombination between phage and prophage depends on the bacterial recF gene. It has been shown that in E. coli K12 postconjugational recombination, the RecF pathway only works with full efficiency if exonuclease I is absent (Clark 1973). However, results presented in this paper indicate that under conditions in which lambda replication is blocked, the recombination pathway dependent on the recF gene is fully active in producing viral recombinants even, if the phage is Red+, in the presence of exonuclease I. In contrast, removal of lambda exonuclease and beta protein requires elimination of exonuclease I for an efficient RecF pathway. It is concluded that the Red system cooperates with the RecF pathway and that this cooperation involves overcoming the inhibitor effects of exonuclease I. In the absence of lambda exonuclease, beta protein stimulates recF-dependent recombination but does not suffice to prevent the negative effect of exonuclease I. In the presence of beta protein, full efficiency of the RecF pathway can be obtained either via cooperation with lambda exonuclease I or, if the viral exonuclease is defective, via inactivation of exonuclease I. Since activity of lambda exonuclease appears necessary to overcome the inhibitory effects of exonuclease I, it is proposed here that lambda exonuclease diverts material from the RecF pathway in a shunt reaction which allows completion of recF-initiated recombinational intermediates via a mechanism insensitive to exonuclease I. When lambda replication is allowed, the Rec system produces viral recombinants mainly via a recF-independent mechanism. However, a major contribution to the RecF pathway to lambda recombination is observed after removal of the Red system and exonuclease.
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PMID:Role of the recF gene of Escherichia coli K-12 in lambda recombination. 626 23

Interplasmidic and intraplasmidic recombination proficiencies were determined in E. coli bacterial strains carrying rec mutations. Our results defined the role of recF gene function, recB, recC, and sbcB gene products (exonuclease V and exonuclease I) in plasmidic recombination in wild-type E. coli cells and in cells in which the recE recombination pathway is activated. RecF gene function is required for interplasmidic recombination regardless of the recB recC genotype. Intraplasmidic recombination is recF dependent in cells having a functional exonuclease V, but not in recB recC mutants. Exonuclease V activity inhibits both interplasmidic and intraplasmidic recombination via the recE pathway.
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PMID:Plasmidic recombination in Escherichia coli K-12: the role of recF gene function. 634 18

During infection of homoimmune Escherichia coli lysogens ("repressed infections"), undamaged nonreplicating lambda phage DNA circles undergo very little recombination. Prior UV irradiation of phages dramatically elevates recombinant frequencies, even in bacteria deficient in UvrABC-mediated excision repair. We previously reported that 80-90% of this UvrABC-independent recombination required MutHLS function and unmethylated d(GATC) sites, two hallmarks of methyl-directed mismatch repair. We now find that deficiencies in other mismatch-repair activities--UvrD helicase, exonuclease I, exonuclease VII, RecJ exonuclease--drastically reduce recombination. These effects of exonuclease deficiencies on recombination are greater than previously observed effects on mispair-provoked excision in vitro. This suggests that the exonucleases also play other roles in generation and processing of recombinagenic DNA structures. Even though dsDNA breaks are thought to be highly recombinagenic, 60% of intracellular UV-irradiated phage DNA extracted from bacteria in which recombination is low--UvrD-, ExoI-, ExoVII-, or Rec(J-)--displays (near-)blunt-ended dsDNA ends (RecBCD-sensitive when deproteinized). In contrast, only bacteria showing high recombination (Mut+ UvrD+ Exo+) generate single-stranded regions in nonreplicating UV-irradiated DNA. Both recF and recB recC mutations strikingly reduce recombination (almost as much as a recF recB recC triple mutation), suggesting critical requirements for both RecF and RecBCD activity. The mismatch repair system may thus process UV-irradiated DNA so as to initiate more than one recombination pathway.
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PMID:DNA structures generated during recombination initiated by mismatch repair of UV-irradiated nonreplicating phage DNA in Escherichia coli: requirements for helicase, exonucleases, and RecF and RecBCD functions. 749 61