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)

The nonconjugative plasmid, pVS1, has a molecular weight of 18.5 X 10(6) and confers resistance to sulfonamides and to mercuric ions. In Pseudomonas aeruginosa PAO, the transfer can be mobilized by a variety of conjugative plasmids, and the process does not require a functional recombination system in the donor. Hybrid plasmids that arise by the relocation of the mer gene onto the mobilizing plasmid can be isolated readily, and, as far as can be determined, these hybrids retain the genome of the conjugative plasmid in toto. The relocation of mer occurs by a Rec-independent process and leads to a constant increase (about 6 X 10(6) daltons) in the size of the recipient plasmid. This suggests that the mer gene in pVS1 is located on a translocation unit, designated Tn501, of a molecular weight of about 6 X 10(6). The translocation of Tn501 into RP1 is not usually associated with the loss of any known plasmid-mediated function, but transfer-defective or tetracycline-sensitive derivatives do occur at frequencies of about 4%, whereas carbenicillin-sensitive or kanamycin-sensitive variants arise with a frequency of about 0.2% each. It seems therefore that the integration of Tn501 can occur at any one of a minimum of five sites in RP1.
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PMID:Characterization of a translocation unit encoding resistance to mercuric ions that occurs on a nonconjugative plasmid in Pseudomonas aeruginosa. 40 73

Recombinant plasmids containing the recA gene from Pseudomonas aeruginosa were used in complementation, transcriptional, and translational studies to examine the nature of rec-102 and rec-2, mutations which confer a recA-like mutant phenotype on P. aeruginosa PAO strains. For comparison, recA7::Tn501 mutants of strain PAO were constructed by gene replacement. The rec-2 and rec-102 alleles were shown to be recA alleles; plasmids containing the recA gene complemented the three rec mutant strains for defects associated with recA mutation. Northern blot analyses indicated that the recA gene in P. aeruginosa was transcribed as two distinct mRNAs of approximately 1.2 and 1.4 kilobases (kb). A plasmid encoding both transcripts of recA complemented all defects associated with the three recA mutations rec-2, rec-102, and recA7. However, a 2.4-kb subclone (pJH13) encoding only the smaller transcript of the recA gene was expressed differently in the three recA allele backgrounds and served as a tool to distinguish the nature of the rec-2 and rec-102 mutations in recA. A minicell analysis showed that a plasmid expressing both of the recA gene transcripts or one that expressed only the smaller transcript both produced the same 42-kilodalton recA protein. A chloramphenicol acetyltransferase gene fusion in the 3' end of the recA transcript showed that the recA gene of P. aeruginosa was induced following treatment with a DNA-damaging agent (methyl methanesulfonate). The recA7 mutant constructed here showed no recA-related transcript or protein under inducing conditions, and pJH13 in this host produced only low levels of the smaller recA transcript and low levels of recA protein. The rec-2 mutant produced a detectable transcript but no recA protein following induction. The presence of low levels of activated recA protein encoded by pJH13 in the rec-2 mutant resulted in wild-type transcriptional levels of chromosomally encoded recA, but no recA protein was detectable. Thus, the rec-2 allele of recA was normal with respect to induction of mRNA, but these transcripts were defective in either translation or synthesis of a stable protein. The rec-102 mutant also produced a detectable transcript and no recA protein following induction, but having pJH13 in the cell to produce low levels of activated recA protein resulted in overproduction of chromosomally encoded recA transcripts and active recA protein. Thus, the recA defect in the rec-102 mutant is apparently in the interaction between recA and a lexA-like repressor.
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PMID:Transcriptional and translational analyses of recA mutant alleles in Pseudomonas aeruginosa. 245 Aug 68

Two Haemophilus influenzae Rd genes each complemented the pleiotropic defects of the recA-like mutation rec-1. One gene, fec, was isolated on a 3.6-kilobase-pair EcoRI restriction fragment by complementation of the Fec- phenotype of bacteriophage lambda. The other gene, rec, was identified on a 3.1-kilobase-pair EcoRI fragment by Southern hybridization by using recA-like gene probes from Erwinia carotovora and Pseudomonas aeruginosa PAO. In a rec-1 strain of H. influenzae, the cloned genes restored resistance to UV irradiation, transformation by chromosomal DNA, and spontaneous release of HP1 prophage to wild-type levels. The fec and rec genes were located on the cloned segments by insertion and deletion mutagenesis and subcloning. The restriction endonuclease cleavage maps of the two DNAs were similar but not identical. Southern hybridization demonstrated that the two EcoRI restriction fragments contained homologous DNA sequences, but a fec gene-specific probe was prepared. Each gene encoded a 38,000-dalton polypeptide.
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PMID:Two Haemophilus influenzae Rd genes that complement the recA-like mutation rec-1. 278 4

For insertional mutagenesis of Pseudomonas aeruginosa, a derivative of the kanamycin-resistance (KmR) transposon Tn5 was constructed (Tn5-751) that carried the trimethoprim-resistance (TpR) determinant from plasmid R751 as an additional marker. Double selection for KmR and TpR avoided the isolation of spontaneous aminoglycoside-resistant mutants which occur at high frequencies in P. aeruginosa. As a delivery system for the recombinant transposon, plasmid pME305, a derivative of the broad-host-range plasma RP1, proved effective; pME305 is temperature-sensitive at 43 degrees C for maintenance in Escherichia coli and P. aeruginosa and deleted for IS21 and the KmR and primase genes. In matings with an E. coli donor carrying pME9(= pME305::Tn5-751), transposon insertion mutants of P. aeruginosa PAO were recovered at approx. 5 X 10(-7)/donor at 43 degrees C. Among Tn5-751 insertional mutants 0.9% were auxotrophs. A thr::Tn5-751 mutation near the recA-like locus rec-102 is useful for the construction of recombination-deficient strains. Several arc::Tn5-751 mutants could be isolated that were defective in anaerobic utilization of arginine as an energy source. From three of these mutants the arc gene region was cloned into an E. coli vector plasmid. Since Tn5-751 has a single EcoRI site between the TpR and KmR genes, EcoRI-generated fragments carrying either resistance determinant plus adjacent chromosomal DNA could be selected separately in E. coli. Thus, a restriction map of the arc region was constructed and verified by hybridization experiments. The arc genes were tightly clustered, confirming earlier genetic evidence.
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PMID:Transposon insertion mutagenesis of Pseudomonas aeruginosa with a Tn5 derivative: application to physical mapping of the arc gene cluster. 298 92

Broad host range IncP-1 plasmids are able to integrate into the chromosome of gram-negative bacteria. Strains carrying an integrated plasmid can be obtained when the markers of a temperature-sensitive (ts) plasmid derivative are selected at non-permissive temperature; in this way Hfr (high frequency) donor strains can be formed. The integrated plasmids, however, tend to be unstable in the absence of continuous selective pressure. In order to obtain stable Hfr donor strains of Pseudomonas aeruginosa PAO, we constructed a derivative of an RP1 (ts) plasmid, pME134, which was defective in the resolvase gene (tnpR) of transposon Tn801. Chromosomal integration of pME134 was selected in a recombination-deficient (rec-102) PAO strain at 43 degrees C. Plasmid integration occurred at different sites resulting in a useful set of Hfr strains that transferred chromosomal markers unidirectionally. The tnpR and rec-102 mutations prevented plasmid excision from the chromosome. In several (but not all) Hfr strains that grew well and retained the integrated plasmid at temperatures below 43 degrees C, the insertion element IS21 of RP1 was found to be inserted into the trfA locus (specifying an essential trans-acting replication function) of the integrated plasmid. One such Hfr strain was rendered rec+; from its chromosome the pME134::IS21 plasmid (= pME14) was excised and transferred by conjugation to Escherichia coli where pME14 could replicate autonomously only when a helper plasmid provided the trfA+ function in trans. Thus, it appears that trfA inactivation favours the stability of chromosomally integrated RP1 in P. aeruginosa.
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PMID:IS21 insertion in the trfA replication control gene of chromosomally integrated plasmid RP1: a property of stable Pseudomonas aeruginosa Hfr strains. 301 34

We cloned a 2.3-kilobase-pair fragment of the Pseudomonas aeruginosa PAO chromosome which is capable of complementing recA mutations of Escherichia coli. The recA-complementing activity was further localized to a 1.5-kilobase-pair PvuII-HindIII fragment. Southern blot analysis under conditions of high stringency indicated that DNA sequence homology is shared by the E. coli recA gene and the P. aeruginosa recA analog. The cloned recA analog was shown to restore resistance to methyl methanesulfonate, nitrofurantoin, and UV irradiation to E. coli recA mutants. Upon introduction of the cloned P. aeruginosa gene, these mutants regained recombination proficiency in HfrH-mediated conjugation and the ability to induce lambda prophages and SOS functions (din gene transcription) after exposure to DNA-damaging agents. Lambda prophage carrying a cI ind mutation was not inducible, suggesting that the mechanism of induction of these SOS functions by the P. aeruginosa RecA analog is similar to that by the activated E. coli RecA protein. The product of the recA analog was identified in minicells as a protein of approximately 47,000 daltons. Western blot analysis using anti-E. coli RecA antibody demonstrated that this protein is antigenically cross-reactive with the E. coli recA protein. The recA-containing fragment was cloned into the broad-host-range vector pCP13 and introduced into Rec- strains of P. aeruginosa containing the rec-102 allele. The plasmid was shown to restore recombination proficiency in FP5-mediated conjugations and to restore resistance to UV irradiation and methyl methanesulfonate to these Rec- mutants. It was shown that a wild-type allele of rec-102 is necessary for UV-mediated induction of D3 and F116 prophages. The cloned recA analog restored the UV inducibility of these prophages in rec-102 mutants. These data indicate that rec-102 is a mutant allele of the P. aeruginosa recA gene and suggest that there has been considerable conservation of the recA gene in the evolution of the gram-negative bacteria.
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PMID:Characterization of the Pseudomonas aeruginosa recA analog and its protein product: rec-102 is a mutant allele of the P. aeruginosa PAO recA gene. 303 Oct 14

Several hybrid RP4 plasmids containing the genome of heat-inducible D3112cts15 phage integrated into 2 different sites of RP4 were selected. It was shown that the plasmids RP4::D3112cts15 mobilized the chromosome of Pseudomonas aeruginosa from many sites located in different chromosome regions. Chromosomal recombinants are, formed at frequencies of about 10(-4) per recipient cell. Analysis of coinheritance of unselected markers showed that the majority of recombinants inherited short donor chromosome fragments (about 5 min). R' plasmids can be easily selected by mating with a rec- recipient. For instance, the frequency of selection of R' plasmids containing argH+ locus was about 10(-5) per donor cell. Conjugative transfer of RP4::D3112cts15 into nonlysogenic strains PAO P. aeruginosa results in partial or complete loss of prophage from a hybrid plasmid. The RP4::D3112cts15 plasmids appear to have retained the broad host range of the original RP4 (they are maintained in P. putida and Escherichia coli).
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PMID:[Transfer of chromosomal genes and formation of R'-derivatives using PR4::D312cts15 plasmids in Pseudomonas aeruginosa cells]. 310 Mar 92

In Pseudomonas aeruginosa strain PAO the chromosome-mobilizing IncP-1 plasmid R68.45 was unstable whereas the parent plasmid R68 was stable. The instability of R68.45 was observed in rec+ and rec strains within about 100 generations after conjugal transfer of the plasmid and, to a lesser extent, in established R68.45 donor strains. Two phenotypically distinct classes of R68.45 derivatives were obtained: (i) CbR (carbenicillin-resistant), TcR (tetracycline-resistant), KmR (kanamycin-resistant), Tra+ (transfer proficient), Cma- (chromosome-mobilizing ability), lacking the duplicated IS21 copy typical of R68.45 and indistinguishable from R68 by restriction enzyme analysis; (ii) CbR TcR KmS Tra- Cma-, due to deletion of one IS21 copy, the adjacent KmR gene, and a variable part of the Tra-1 region including, in most cases, the origin of transfer (oriT). Both types of deletion derivatives were stable. R68.45 derivatives lacking the Tra-2 region were not recovered spontaneously, but could be constructed in vitro and were stable in strain PAO. Deletion formation of type ii as well as Cma did not depend on homologous recombination and can be ascribed to functions of the duplicated IS21. Chromosome mobilization does not appear to require obligatory transfer of the entire R68.45 plasmid. Four ClaI restriction sites were mapped on R68 extracted from P. aeruginosa. One of these sites was cryptic, presumably because of methylation, when the plasmid was prepared from Escherichia coli (dam+).
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PMID:Spontaneous deletions of the chromosome-mobilizing plasmid R68.45 in Pseudomonas aeruginosa PAO. 630 Sep 44

The rec-102 mutation had pleiotropic effects in Pseudomonas aeruginosa: low recombinational proficiency in conjugation and transduction; high UV sensitivity; inability to induce pyocin R2 by mitomycin C; and increased susceptibility to mitomycin C and nalidixic acid. The rec-102 locus was mapped by R68.45-mediated conjugation in the 45 min region of the PAO chromosome, between argF and thr-9001. By selection for a marker in this region, rec-102 can be introduced into a P. aeruginosa strain of interest using an R68.45 rec-102 donor. The recombination-deficient strains constructed in this way were phenotypically similar to Escherichia coli recA mutants.
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PMID:Construction of recombination-deficient strains of Pseudomonas aeruginosa. 641 24