Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| the xyls gene positive regulator of tol plasmid pwwo: identification, sequence analysis and overproduction leading to constitutive expression of meta cleavage operon. | the pseudomonas putida tol plasmid pwwo carries an operon that specifies a meta-cleavage pathway for the catabolism of benzoate and toluates whose transcription is positively regulated by the xyls gene product. stimulation of transcription of the operon is thought to result from activation of this protein by pathway substrates/effectors. in the present study, overexpression of the xyls gene has led to identification of the regulator as a 33 kda protein. overexpression of xyls also resulted in pa ... | 1987 | 3475526 |
| evolutionary relationships between catabolic pathways for aromatics: conservation of gene order and nucleotide sequences of catechol oxidation genes of pww0 and nah7 plasmids. | tol plasmid pww0 and plasmid nah7 encode catabolic enzymes required for oxidative degradation of toluene and naphthalene, respectively. the gene order of the catabolic operon of nah7 for salicylate oxidation was determined to be: promoter--nahg (the structural gene for salicylate hydroxylase)--nahh (catechol 2.3-dioxygenase)--nahi (hydroxymuconic semialdehyde dehydrogenase)--nahn (hydroxymuconic semialdehyde hydrolase)--nahl (2-oxopent-4-enoate hydratase). this order is identical to that of the ... | 1987 | 3481421 |
| the xylabc promoter from the pseudomonas putida tol plasmid is activated by nitrogen regulatory genes in escherichia coli. | the xylabc promoter (op1), located on the tol plasmid of pseudomonas putida contains sequences homologous to the conserved regions found in nitrogen fixation (nif) promoters and in other promoters subject to nitrogen control. xyla-lac fusions were constructed in order to monitor expression from the op1 promoter in escherichia coli. transcription was activated in the presence of the heterologous regulatory genes ntrc or nifa from klebsiella pneumoniae as well as by the homologous p. putida regula ... | 1986 | 3520241 |
| vector for regulated expression of cloned genes in a wide range of gram-negative bacteria. | a pkt231-based broad-host-range plasmid vector was constructed which enabled regulation of expression of cloned genes in a wide range of gram-negative bacteria. this vector, pnm185, contained upstream of its ecori, ssti, and sstii cloning sites the positively activated pm twin promoters of the tol plasmid and xyls, the gene of the positive regulator of these promoters. expression of cloned genes was induced with micromolar quantities of benzoate or m-toluate, the inexpensive coinducers of the pm ... | 1986 | 3525513 |
| roles of the divergent branches of the meta-cleavage pathway in the degradation of benzoate and substituted benzoates. | the tol plasmid-specified meta-cleavage pathway for the oxidative catabolism of benzoate and toluates branches at the ring cleavage products of catechols and reconverges later at 2-oxopent-4-enoate or its corresponding substituted derivatives. the hydrolytic branch of the pathway involves the direct formation of 2-oxopent-4-enoate or its derivatives, whereas the oxalocrotonate branch involves three enzymatic steps effected by a dehydrogenase, an isomerase, and a decarboxylase, which produce the ... | 1987 | 3542963 |
| overproduction of the xyls gene product and activation of the xyldlegf operon on the tol plasmid. | the effect of high-level expression of the regulatory gene xyls of the pseudomonas putida tol plasmid on the activation of the xyldlegf operon was investigated in escherichia coli. the xyls gene was placed downstream from the tac promoter, and the resultant fusion was cloned in cis to the xyldlegf operon. the expression of the operon was monitored by the level of catechol 2,3-dioxygenase, whose structural gene xyle was placed directly after the operator-promoter region of xyldlegf. xyls transcri ... | 1987 | 3611023 |
| nucleotide sequence and expression of gene nahh of plasmid nah7 and homology with gene xyle of tol pwwo. | the enzyme catechol 2,3-dioxygenase (c23o) encoded by the nahh gene of plasmid nah7 converts catechol to alpha-hydroxymuconic epsilon-semialdehyde in pseudomonas putida. we have cloned this structural gene into vectors puc18 and pkt240, determined the nucleotide sequence and deduced the amino acid sequence. in comparison to the gene xyle of the tol plasmid pwwo which encodes a similar c230 enzyme [nakai et al. j. biol. chem. (1983b), 2923-2928], the respective g + c contents were 55% and 57%, th ... | 1987 | 3623105 |
| the effect of lipophilic weak acids on the segregational stability of tol plasmids in pseudomonas putida. | the effect of various lipophilic weak acids on the stability of certain tol plasmids was investigated. benzoate induced deletion of tol plasmid dna in pseudomonas putida mt15, followed by loss of the plasmid; this effect was ph- and concentration-dependent, suggesting that undissociated benzoic acid was a more effective curing agent than the benzoate anion. plasmid loss always approached a frequency of 100% after a lag and apparently depended on the prior occurrence of deletions, although delete ... | 1987 | 3668501 |
| identification of cis-diols as intermediates in the oxidation of aromatic acids by a strain of pseudomonas putida that contains a tol plasmid. | pseudomonas putida bg1 was isolated from soil by enrichment with p-toluate and selection for growth with p-xylene. other hydrocarbons that served as growth substrates were toluene, m-xylene, 3-ethyltoluene, and 1,2,4-trimethylbenzene. the enzymes responsible for growth on these substrates are encoded by a large plasmid with properties similar to those of tol plasmids isolated from other strains of pseudomonas. treatment of p. putida bg1 with nitrosoguanidine led to the isolation of a mutant stra ... | 1986 | 3711022 |
| chromosomal location of tol plasmid dna in pseudomonas putida. | the soil isolate pseudomonas putida mw1000 can grow on toluene and other hydrocarbons; in this respect it is similar to strains of pseudomonas which carry the tol plasmid. by conjugation experiments, the genes conferring these growth abilities have been shown to be located on the bacterial chromosome, linked to vil and catb. a 56-kilobase segment of the bacterial chromosome of mw strains carrying the tol genes can transpose to the incp-1 plasmid r18-18. physical analysis of these tol r18-18 hybr ... | 1986 | 3782038 |
| adaptation of pseudomonas putida mt-2 to growth on aromatic amines. | pseudomonas putida mt-2 (atcc 33015) carrying the tol plasmid pww0 could adapt to growth on the aromatic amines aniline and m- and p-toluidine. in strain ucc2, a derivative adapted to rapid growth on these compounds, they were oxidatively deaminated to catechol or 4-methylcatechol, which in turn were dissimilated by a meta-cleavage pathway. the aniline/toluidine oxygenase and the meta-cleavage pathway enzymes were inducible by aromatic amines. evidence is presented that in strain ucc2, plasmid p ... | 1986 | 3794647 |
| identification of the promoter of the pseudomonas gene coding for carboxypeptidase g2. | a 213-bp region of noncoding dna upstream of the atg start codon of the pseudomonas carboxypeptidase g2 (cpg2) structural gene has been shown to contain the cpg2 promoter. the mrna start point (+1) on the dna sequence has been identified by mapping the 5' end of the cpg2 transcript. the identified promoter region contains a -10 region (tataag) that closely resembles the escherichia coli consensus sequence (tataat), but has no easily recognisable -35 region. the lack of homology in the -35 region ... | 1985 | 3839252 |
| use of cloned genes of pseudomonas tol plasmid to effect biotransformation of benzoates to cis-dihydrodiols and catechols by escherichia coli cells. | dna fragments containing the xyld and xyll genes, which specify the broad-specificity enzymes toluate-1,2-dioxygenase and 3,5-cyclohexadiene-1,2-diol-1-carboxylic acid dehydrogenase, respectively, of tol plasmid pww0-161 of pseudomonas putida have previously been cloned in the pbr322 vector plasmid (p.r. lehrbach, j. zeyer, w. reinecke, h.-j. knackmuss, and k. n. timmis, j. bacteriol. 158:1025-1032, 1984). in this study, escherichia coli cells containing hybrid plasmids carrying the cloned xyld ... | 1985 | 3911905 |
| application of dna-dna colony hybridization to the detection of catabolic genotypes in environmental samples. | the application of preexisting dna hybridization techniques was investigated for potential in determining populations of specific gene sequences in environmental samples. cross-hybridizations among two degradative plasmids, tol and nah, and two cloning vehicles, plafr1 and rsf1010, were determined. the detection limits for the tol plasmid against a nonhomologous plasmid-bearing bacterial background was ascertained. the colony hybridization technique allowed detection of one colony containing tol ... | 1985 | 4004244 |
| tol plasmid pww15 contains two nonhomologous, independently regulated catechol 2,3-oxygenase genes. | pseudomonas putida mt15 contains a 250-kilobase-pair (kbp) tol plasmid pww15, encoding toluene and xylene catabolism, which undergoes large spontaneous deletions to give two classes of mutants with altered catabolic phenotypes (h. keil and p. a. williams, j. gen. microbiol, 131:1023-1033, 1985). two structural genes for catechol 2,3-oxygenase (c23o) were cloned from pww15. the gene for c23oi was located on the 2.1-kbp xhoi fragment xh, whereas that for c23oii was found on the 11.5-kbp bamhi frag ... | 1985 | 4008443 |
| metabolism of benzoate and the methylbenzoates by pseudomonas putida (arvilla) mt-2: evidence for the existence of a tol plasmid. | mutant strains of pseudomonas putida (arvilla) mt-2 which have lost the ability to grow at the expense of m- or p-toluate (methylbenzoate) but retain the ability to grow with benzoate arise spontaneously during growth on benzoate; this genetic loss occurs to a lesser extent during growth on nonaromatic carbon sources in the presence of mitomycin c. the mutants have totally lost the activity of the enzymes of the divergent meta pathway with the possible exception of 2-oxopent-4-enoate hydratase a ... | 1974 | 4418209 |
| transposon mutagenesis analysis of meta-cleavage pathway operon genes of the tol plasmid of pseudomonas putida mt-2. | hybrid plasmids containing the regulated meta-cleavage pathway operon of tol plasmid pwwo were mutagenized with transposon tn1000 or tn5. the resulting insertion mutant plasmids were examined for their ability to express eight of the catabolic enzymes in escherichia coli. the physical locations of the insertions in each of 28 tn1000 and 5 tn5 derivative plasmids were determined by restriction endonuclease cleavage analysis. this information permitted the construction of a precise physical and ge ... | 1984 | 6090417 |
| nucleotide sequence of the promoter region of the xyldegf operon on tol plasmid of pseudomonas putida. | the transcription initiation site of the xyldegf operon on the tol plasmid of pseudomonas putida mt-2 was determined in p. putida and in escherichia coli by s1 nuclease and reverse transcriptase mapping. the induced synthesis of mrna started at the same start point in both p. putida and e. coli, although the amount of mrna in e. coli cells was less than that in p. putida. the nucleotide sequence of the region surrounding the start point was also determined. the ribosome-binding site (rbs) comple ... | 1984 | 6092237 |
| transcription of the tol plasmid toluate catabolic pathway operon of pseudomonas putida is determined by a pair of co-ordinately and positively regulated overlapping promoters. | expression of the meta-cleavage pathway operon of tol plasmid pww0 of pseudomonas putida is positively regulated by the xyls gene product. we have sequenced the promoter region of this operon and localized the transcription initiation sites. two overlapping promoters, designated pm1 and pm2, are responsible for the positively regulated expression of the meta-pathway operon. mutants of p. putida were isolated that expressed the meta-cleavage pathway operon constitutively. several plasmid-located ... | 1984 | 6096122 |
| the tol plasmid is naturally derepressed for transfer. | pseudomonas putida mt-2, formerly known as pseudomonas arvilla mt-2, which carries the wild-type tol plasmid, and p. putida strain ac37 carrying tol, were completely lysed by the pilus-adsorbing plasmid-specific bacteriophages pr4 and prd1. pseudomonas putida strain pps388, also harbouring the plasmid, was not lysed. in a p. putida mt-2 host, tol transferred 18-fold better on a surface (2.5 x 10(-1) transconjugants per donor h-1) than in liquid; when p. putida pps388 was the host, however, a fre ... | 1982 | 6134782 |
| [tol-plasmid-specific mrna study]. | 1982 | 6179726 | |
| localization and functional analysis of transposon mutations in regulatory genes of the tol catabolic pathway. | mutant derivatives of the tol plasmid pww0-161, containing tn5 insertions in the xyls and xylr regulatory genes of the catabolic pathway, have been identified and characterized. the two genes are located together on a 1.5- to 3.0-kilobase segment of tol, just downstream of genes of the enzymes of the meta-cleavage pathway. as predicted by a current model for regulation of the tol catabolic pathway, benzyl alcohol dehydrogenase, a representative enzyme of the upper (hydrocarbon leads to carboxyli ... | 1983 | 6188746 |
| physical and functional mapping of rp4-tol plasmid recombinants: analysis of insertion and deletion mutants. | cleavage sites for the restriction endonucleases xhoi, bamhi, hindiii, and ecori were mapped on the ptn2 plasmid, a recombinant of tol and rp4, which specifies the toluene-degrading enzymes in the same way as the wild-type tol plasmid. the ptn2 plasmid, purified from a strain of escherichia coli, contained the entire length of the rp4 plasmid (about 54 kilobase pairs [kb]) and the tol segment (about 56 kb). the tol segment is inserted at about 12 and 5 kb away from the ecori and bamhi cleavage s ... | 1980 | 6252192 |
| molecular cloning of gene xyls of the tol plasmid: evidence for positive regulation of the xyldegf operon by xyls. | the xyldegf operon and the regulatory gene xyls of the tol plasmid found in pseudomonas putida mt-2 were cloned onto escherichia coli vector plasmids. a 9.5-kilobase fragment, derived from the tol segment of ptn2 deoxyribonucleic acid, carried the xyl genes d, e, g, and f, which encode toluate oxygenase, catechol 2,3-oxygenase, 2-hydroxymuconic semialdehyde dehydrogenase, and 2-hydroxymuconic semialdehyde hydrolase, respectively. the enzymes were noninducible unless a 3-kilobase psti fragment, d ... | 1981 | 6271729 |
| plasmid gene organization: naphthalene/salicylate oxidation. | genes for naphthalene metabolism are localized on nah7, an 83-kilobase (kb) plasmid, in two gene clusters under salicylate control. polar mutations formed by insertion of the transposon tn5 permit detection of the transcription direction and the gene organization within two approximately 10-kb dna segments separated by a approximately 7-kb regulatory gene region. the gene cluster specifying conversion of naphthalene to salicylate lies near the left initiation of a 25-kb dna fragment a released b ... | 1982 | 6278499 |
| spontaneous deletions in the tol plasmid pww20 which give rise to the b3 regulatory mutants of pseudomonas putida mt20. | the size of the tol plasmid pww20 from pseudomonas putida mt20, as measured by analysis of agarose electrophoresis gels after restriction endonuclease hydrolysis, was 270-280 kilobase pairs (kb). during growth on benzoate, mt20 segregates strains carrying mutations in the plasmid regulatory gene xyls; these so-called b3 strains retain the ability to grow on m-xylene (mxy+) but do not grow on its metabolite m-toluate (mtol-) and have also lost the ability to transfer the plasmid (tra-). analysis ... | 1982 | 6288840 |
| identification of chromosomally integrated tol dna in cured derivatives of pseudomonas putida paw1. | some plasmid-free tol- strains derived from pseudomonas putida paw1 (which carries the tol plasmid pww0) have a segment of tol dna located chromosomally. of three independently isolated strains, paw86 had an integrated tol segment of 16 kilobases and paw85 had two copies of this segment in different chromosomal locations, whereas the chromosomal dna of paw82 showed no homology with the tol plasmid. in cultures of the parental strain, it appears that a 56-kilobase tol dna segment is located chrom ... | 1982 | 6290457 |
| characterization by molecular cloning of insertion mutants in tol catabolic functions. | a physical and genetic map of the tol catabolic region of pwwo (tol) was obtained by restriction endonuclease analysis of several dna insertion mutants (xyla, xyla xyls, xyls, and xylr) of r plasmid--tol derivatives. in two cases, the inserted dna was shown from restriction, dna hybridization, or heteroduplex analysis of cloned hind iii fragments to originate from within pwwo fragment hind iii-e. the effect of these dna insertions on tol catabolic activity and on structural alterations to the to ... | 1983 | 6304792 |
| plasmid-encoded regulation of colicin e1 gene expression. | a plasmid-encoded factor that regulates the expression of the colicin e1 gene was found in molecular cloning experiments. the 2,294-base-pair avaii fragment of the colicin e1 plasmid (cole1) carrying the colicin e1 structural gene and the promoter-operator region had the same information with respect to the repressibility and inducibility of colicin e1 synthesis as the original cole1 plasmid. an operon fusion was constructed between the 204-bp fragment containing the colicin e1 promoter-operator ... | 1983 | 6313603 |
| nucleotide sequence surrounding transcription initiation site of xylabc operon on tol plasmid of pseudomonas putida. | the xylabc operon on the tol plasmid directs the synthesis of enzymes for conversion of toluene to benzoate and is positively controlled by the regulatory gene xylr. in the study here the nucleotide sequence was determined for the regulatory region of this operon. the in vivo transcription initiation site of the operon was determined by s1 nuclease and reverse transcriptase mapping. rna was prepared from m-methylbenzyl alcohol-induced cells of pseudomonas putida and escherichia coli carrying ptn ... | 1984 | 6324212 |
| characterization of a tol-like plasmid from alcaligenes eutrophus that controls expression of a chromosomally encoded p-cresol pathway. | alcaligenes eutrophus wild-type strain 345 metabolizes m- and p-toluate via a catechol meta-cleavage pathway. dna analysis, curing studies, and transfer of this phenotype by conjugation and transformation showed that the degradative genes are encoded on a self-transmissible 85-kilobase plasmid, pra1000. hindiii and xhoi restriction endonuclease analysis of pra1000 showed it to be similar to the archetypal tol plasmid, pwwo, differing in the case of hindiii only by the absence of fragments b and ... | 1984 | 6325399 |
| enzyme recruitment in vitro: use of cloned genes to extend the range of haloaromatics degraded by pseudomonas sp. strain b13. | dna fragments containing the xyld and xyll genes of tol plasmid pww0 -161 of pseudomonas putida, which code for the catabolic enzymes toluate 1,2-dioxygenase and dihydrodihydroxybenzoic acid dehydrogenase, respectively, and the nahg gene of the nah plasmid nah7 , which codes for salicylate hydroxylase, were cloned in pbr322 vector plasmid. deletion and insertion mutagenesis were used to localize these genes with respect to crucial endonuclease cleavage sites. the pbr322-based plasmids were ligat ... | 1984 | 6327621 |
| chromogenic identification of genetic regulatory signals in bacillus subtilis based on expression of a cloned pseudomonas gene. | a method to isolate fragments of dna that promote gene expression in bacillus subtilis is described. the system is based on production of catechol 2,3-dioxygenase [cato2ase; catechol:oxygen 2,3-oxidoreductase (decyclizing), ec 1.13.11.2] encoded by the pseudomonas putida tol plasmid gene xyle. the gene was transferred to ab. subtilis/escherichia coli plasmid vector to construct ptg402. although xyle is functionally expressed in e. coli, cato2ase is not detected in b. subtilis unless a fragment o ... | 1983 | 6405380 |
| tol plasmid can prevent induction of chemotactic responses to aromatic acids. | growth conditions that elicited positive chemotaxis to benzoate and m-toluate in tol- pseudomonas putida cells failed to elicit taxis to these compounds in tol+ cells. the inability of tol+ cells to respond to these aromatic acids appears to be due to the preferential expression of tol-encoded genes for aromatic degradation over chromosomally encoded genes. expression of chromosomal genes for aromatic degradation is required for cells to form beta-ketoadipate, the inducer of benzoate and m-tolua ... | 1984 | 6501222 |
| complete nucleotide sequence of the metapyrocatechase gene on the toi plasmid of pseudomonas putida mt-2. | metapyrocatechase which catalyzes the oxygenative ring cleavage of catechol to form alpha-hydroxymuconic epsilon-semialdehyde is encoded by the xyle gene on the tol plasmid of pseudomonas putida mt-2. we have cloned the xyle region in escherichia coli and determined the nucleotide sequence of the dna fragment of 985 base pairs around the gene. the fragment included only one open translational frame of sufficient length to accommodate the enzyme. the predicted amino acid sequence consisted of 307 ... | 1983 | 6826546 |
| molecular cloning of regulatory gene xylr and operator-promoter regions of the xylabc and xyldegf operons of the tol plasmid. | the regulatory gene xylr of the tol plasmid, which functions positively on both xylabc and xyldegf operons in the presence of m-xylene or m-methylbenzyl alcohol, was cloned onto an escherichia coli vector, pacyc177. a fused operon consisting of the operator-promoter region of the xylabc operon and the xyle gene was cloned onto pbr322. the xyle product, catechol 2,3-dioxygenase, was induced by m-xylene or m-methylbenzyl alcohol in the cells containing the fused operon when a 2.8-kilobase segment ... | 1983 | 6885718 |
| construction of a partial diploid for the degradative pathway encoded by the tol plasmid (pwwo) from pseudomonas putida mt-2: evidence for the positive nature of the regulation by the xyir gene. | 1980 | 6929031 | |
| excision of the 40kb segment of the tol plasmid from pseudomonas putida mt-2 involves direct repeats. | 1981 | 6950198 | |
| molecular and functional analysis of the tol plasmid pwwo from pseudomonas putida and cloning of genes for the entire regulated aromatic ring meta cleavage pathway. | the genetic organization of the pseudomonas putida plasmid pwwo-161, which encodes enzymes for the degradation of toluene and related aromatic hydrocarbons, has been investigated by transposition mutagenesis and gene cloning. catabolic genes were localized to two clusters, one for upper pathway (hydrocarbon leads to carboxylic acid) enzymes and the other for lower pathway (carboxylic acid leads to tricarboxylic acid cycle) enzymes, that are separated by a 14-kilobase dna segment. the physical or ... | 1981 | 6950388 |
| molecular cloning of tol genes xylb and xyle in escherichia coli. | the xylb and xyle genes in the tol plasmid of pseudomonas putida mt-2, which code for benzyl alcohol dehydrogenase and catechol 2,3-oxygenase, respectively, were cloned onto plasmid pbr322 in escherichia coli for detailed mapping. the xylb gene was mapped in a 2.9-kilobase region within the bamhi bc fragment of ptn2, an in vivo rp4-tol recombinant, whereas the xyle gene was mapped in a 1.8-kilobase region within the bamhi bd fragment. the directions of transcription of these genes were deduced f ... | 1981 | 7009570 |
| tol plasmid pww0 in constructed halobenzoate-degrading pseudomonas strains: enzyme regulation and dna structure. | wr211 and wr216 are derivatives of halobenzoate-degrading pseudomonas sp. strain b13 into which the 117-kilobase tol degradative plasmid pww0 has been transferred from pseudomonas putida mt-2. wr211 has lost the ability to grow on the tol-specific substrate m-xylene but retains the ability to grow on its metabolite, m-toluate. an analysis of the induction of enzymes was consistent with wr211 carrying a nonfunctional regulatory gene, xy1r, wr216 is a spontaneous derivative of wr211 which grows on ... | 1982 | 7061391 |
| excision and integration of degradative pathway genes from tol plasmid pww0. | wr211 is a transconjugant resulting from transfer of the 117-kilobase (kb) tol degradative plasmid pww0 into pseudomonas sp. strain b13. the plasmid of this strain, pww01211, is 78 kb long, having suffered a deletion of 39 kb. we show that wr211 contains the 39 kb that is missing from its plasmid, together with at least an additional 17 kb of pww0 dna integrated in another part of the genome, probably the chromosome. the ability of wr211 to grow on the tol-specific substrate m-toluate is the res ... | 1982 | 7061392 |
| tol plasmid pww0 in constructed halobenzoate-degrading pseudomonas strains: prevention of meta pathway. | the hybrid pathway for chlorobenzoate metabolism was studied in wr211 and wr216, which were derived from pseudomonas sp. b13 by acquisition of tol plasmid pww0 from pseudomonas putida mt-2. chlorobenzoates are utilized readily by these strains when meta cleavage of chlorocatechols is suppressed. when wr211 utilizes 3-chlorobenzoate (3cb), the expression of catechol 2,3-dioxygenase (c23o) and the catabolic activities for chloroaromatics via the ortho pathway coexist as a consequence of inactivati ... | 1982 | 7061393 |
| isolation and characterization of spontaneously occurring tol plasmid mutants of pseudomonas putida hs1. | a strain of pseudomonas (p. putida hs1) was found to resemble p. putida (arvilla) mt-2 in its ability to degrade toluene, m- and p-xylene, 1,2,4-trimethylbenzene (pseudocumene), and 3-ethyltoluene via oxidation of a methyl substituent and reactions of the meta-fission pathway. the ability to degrade these substrates by p. putida hs1 (ppc1) was shown to be encoded by a tol (pdk1) plasmid as evidenced by: (i) spontaneous loss of the tol-related phenotype after growth with benzoate, (ii) transfer o ... | 1981 | 7240090 |
| metabolism of allylglycine and cis-crotylglycine by pseudomonas putida (arvilla) mt-2 harboring a tol plasmid. | spontaneous mutants which acquired the ability to utilize d-allylglycine (d-2-amino-4-pentenoic acid) and dl-cis-crotylglycine (dl-2-amino-cis-4-hexenoic acid) but not l-allylglycine or dl-trans-crotylglycine could be readily isolated from pseudomonas putida mt-2 (pam1). derivative strains of pam1 putatively cured of the tol (pwwo) plasmid were incapable of forming mutants able to utilize the amino acids for growth; however, this ability could be regained by conjugative transfer of the tol (pwwo ... | 1981 | 7287632 |
| hybrid pathway for chlorobenzoate metabolism in pseudomonas sp. b13 derivatives. | derivatives of pseudomonas sp. b13 which had acquired the capability to utilize 4-chloro- and 3,5-dichlorobenzoate as a consequence of the introduction of genes of the tol plasmid of pseudomonas putida mt-2 were studied. the utilization of these substrates, a property not shared by the parent strains, was shown to depend upon the combined activities of enzymes from the donor and from the recipient. during growth on 3-chloro-, 4-chloro-, and 3,5-dichlorobenzoate, predominantly the toluate 1,2-deo ... | 1980 | 7380800 |
| construction and behavior of biologically contained bacteria for environmental applications in bioremediation. | the survival of microorganisms can be predicted through the use of active biological containment systems. we have constructed contained pseudomonas putida strains that degrade alkylbenzoates. the modified strain carries a fusion of the plac promoter to the gef gene, which encodes a killing protein. expression from plac is controlled through a regulatory cascade, so that plac is switched on or off by the absence or presence of alkylbenzoates, respectively. similar uncontained strains were also co ... | 1995 | 7487030 |
| the 4-hydroxy-2-oxovalerate aldolase and acetaldehyde dehydrogenase (acylating) encoded by the nahm and naho genes of the naphthalene catabolic plasmid pww60-22 provide further evidence of conservation of meta-cleavage pathway gene sequences. | we report the complete nucleotide sequence and over-expression of the nahom genes for the acetaldehyde dehydrogenase (acylating) and the 4-hydroxy-2-oxovalerate aldolase from the meta pathway operon of the naphthalene catabolic plasmid pww60-22 from pseudomonas sp. ncimb9816. additional partial sequence analysis of adjacent dna shows the gene order within the operon to be nahnlomk, identical to the order found for the isofunctional genes in the meta pathway operons in the toluene/xylene pathway ... | 1995 | 7496535 |
| quantification of the effect of substrate concentration on the conjugal transfer rate of the tol plasmid in short-term batch mating experiments. | batch mating experiments with pseudomonas putida paw 1 (tol) as a donor and pseudomonas aeruginosa pao 1162 as a recipient strain were performed to quantify the effect of the substrate concentration in the mating medium on the observed plasmid transfer rate coefficient. the impact of the substrate concentration in the mating medium was highly correlated with the growth history of the donor strain. when the donor strain was harvested in exponential growth phase, no impact was observed; when the d ... | 1995 | 7576502 |
| the sigma 54-dependent promoter ps of the tol plasmid of pseudomonas putida requires hu for transcriptional activation in vivo by xylr. | in the presence of toluene and xylenes, the sigma 54-dependent ps promoter of the tol (toluene biodegradation) plasmid pww0 of pseudomonas putida is activated at a distance by the xylr protein, of the ntrc family of transcriptional regulators. since contacts between xylr bound to upstream activating sites and the rna polymerase require the looping out of the intervening dna segment, the intrinsic curvature, the bendability of the corresponding sequence, and the spatial effects of protein-induced ... | 1995 | 7601841 |
| isolation and expansion of the catabolic potential of a pseudomonas putida strain able to grow in the presence of high concentrations of aromatic hydrocarbons. | pseudomonas putida dot-t1 was isolated after enrichment on minimal medium with 1% (vol/vol) toluene as the sole c source. the strain was able to grow in the presence of 90% (vol/vol) toluene and was tolerant to organic solvents whose log p(ow) (octanol/water partition coefficient) was higher than 2.3. solvent tolerance was inducible, as bacteria grown in the absence of toluene required an adaptation period before growth restarted. mg2+ ions in the culture medium improved solvent tolerance. elect ... | 1995 | 7608060 |
| biosensing of benzene derivatives in the environment by luminescent escherichia coli. | sensitive and convenient biosensing of environmental pollutants has been developed by fusing a gene of firefly luciferase to the tol plasmid. tol plasmid of pseudomonas putida encodes a series of enzymes for degradation of benzene and its derivatives. the expression of these enzymes is controlled with the regulating proteins xylr and xyls, whose promoters are activated in the presence of aromatic compounds. the structural gene of firefly luciferase, as a reporter enzyme, was inserted under the c ... | 1995 | 7612210 |
| overexpression of pseudomonas putida catechol 2,3-dioxygenase with high specific activity by genetically engineered escherichia coli. | the cloned xyle gene encoding catechol 2,3-dioxygenase (metapyrocatechase) from tol plasmid in pseudomonas putida mt-2 has been expressed in escherichia coli w3110 to a level of approximately 15% of the total soluble protein. of the total iron in the crude extract, 45% was on the enzyme. the crystallized enzyme from e. coli had higher iron content (3.7 mol/mol enzyme) and specific activity (536 u/mg) than the enzyme from p. putida mt-2. however, no differences were observed in physicochemical, p ... | 1995 | 7629031 |
| integration host factor suppresses promiscuous activation of the sigma 54-dependent promoter pu of pseudomonas putida. | in the presence of m-xylene, the pu promoter of the tol plasmid of pseudomonas putida is activated by the prokaryotic enhancer-binding protein xylr. the intervening dna segment between the upstream activating sequences (uass) and those for rna polymerase binding contains an integration host factor (ihf) attachment site that is required for full transcriptional activity. in the absence of ihf, the pu promoter can be cross-activated by other members of the sigma 54-dependent family of regulatory p ... | 1995 | 7638181 |
| cloning and sequencing of the catechol 2,3-dioxygenase gene of alcaligenes sp. kf711. | the catechol 2,3-dioxygenase is an aromatic ring-fission enzyme catalyzing the conversion of catechol to 2-hydroxymuconic semialdehyde. a catechol 2,3-dioxygenase gene has been cloned from chromosomal dna of alcaligenes sp. kf711, and its sequence was determined. the catechol 2,3-dioxygenase gene was consisted of 927 nucleotides with atg initiation codon and tga termination codon, which can encode a polypeptide of molecular weight 35 kda containing 308 amino acid residues. g+c content of the gen ... | 1995 | 7702624 |
| tetrameric structure and cellular location of catechol 2,3-dioxygenase. | catechol 2,3-dioxygenase from the meta-cleavage pathway encoded on the tol plasmid of pseudomonas putida (pwwo) was investigated by electron microscopy. negatively stained samples of the purified catechol 2,3-dioxygenase revealed that the enzyme consists of four subunits arranged in a tetrahedral conformation. monoclonal antibodies raised against catechol 2,3-dioxygenase showed highly specific reactions and were used to localize the enzyme in escherichia coli (paw31) and p. putida (pwwo), using ... | 1995 | 7710322 |
| substrate specificity differences between two catechol 2,3-dioxygenases encoded by the tol and nah plasmids from pseudomonas putida. | the substrate specificities of two catechol 2,3-dioxygenases, one encoded by xyle on the tol plasmid pww0 and the other encoded by nahh on the nah7 plasmid, were investigated. the xyle catechol 2,3-dioxygenase catalyzes the ring-cleavage of catechol, 3-methylcatechol and 4-methylcatechol. the nahh catechol 2,3-dioxygenase was partially deficient in oxidizing 3-methylcatechol due to defects in two catalytic properties. first, nahh has a lower kcat value for 3-methylcatechol compared to xyle, and ... | 1995 | 7744021 |
| tol plasmid-specified xylene oxygenase is a wide substrate range monooxygenase capable of olefin epoxidation. | xylene oxygenase, which is encoded on the tol plasmid pwwo of pseudomonas putida mt-2, is a key enzyme system in the degradation of toluene and xylenes by this organism. it was expressed in an escherichia coli recombinant strain carrying the xylma structural genes. this recombinant, which expressed xylene oxygenase from the heat-shock induced lambda pl promoter, was analyzed for its potential as a biocatalytic tool so as to effect the oxidation of side chains of aromatic hydrocarbons to the corr ... | 1994 | 7764991 |
| molecular and biochemical characterization of two meta-cleavage dioxygenases involved in biphenyl and m-xylene degradation by beijerinckia sp. strain b1. | beijerinckia sp. strain b1 is able to grow on either biphenyl or m-xylene as the sole source of carbon and is capable of cooxidizing many polycyclic aromatic hydrocarbons. the catabolic pathways for biphenyl and m-xylene degradation are coinduced and share common downstream enzymatic reactions. the catabolic pathway for biphenyl degradation involves two meta-cleavage steps, one for 2,3-dihydroxybiphenyl and a second for catechol. the catabolic pathway for m-xylene involves one m-cleavage step fo ... | 1995 | 7768806 |
| involvement of ihf protein in expression of the ps promoter of the pseudomonas putida tol plasmid. | regulation of the xyl gene operons of the pseudomonas putida tol plasmid is mediated by the products of the downstream clustered and divergently oriented xylr and xyls regulatory genes. the xylr-xyls intergenic region contains the xylr and xyls promoters pr and ps, respectively. a binding site for the xylr activator protein is located upstream of ps and overlapping pr. dnase i footprint experiments showed that one of these sites, which overlaps the recognition site for xylr activator, as well as ... | 1995 | 7768832 |
| overlapping substrate specificities of benzaldehyde dehydrogenase (the xylc gene product) and 2-hydroxymuconic semialdehyde dehydrogenase (the xylg gene product) encoded by tol plasmid pww0 of pseudomonas putida. | two aldehyde dehydrogenases involved in the degradation of toluene and xylenes, namely, benzaldehyde dehydrogenase and 2-hydroxymuconic semialdehyde dehydrogenase, are encoded by the xylc and xylg genes, respectively, on tol plasmid pww0 of pseudomonas putida. the nucleotide sequence of xylc was determined in this study. a protein exhibiting benzaldehyde dehydrogenase activity had been purified from cells of p. putida (pww0) (j. p. shaw and s. harayama, eur. j. biochem. 191:705-714, 1990); howev ... | 1995 | 7868591 |
| single amino acids changes in the signal receptor domain of xylr resulted in mutants that stimulate transcription in the absence of effectors. | the xylr protein positively controls expression from the pseudomonas putida tol plasmid sigma 54-dependent "upper" pathway operon promoter (pu) and the xyls gene promoter (ps), in response to the presence of aromatic effectors. two mutant xylr regulators able to stimulate transcription from pu and ps in the absence of effectors were isolated. these mutants exhibited single point mutations, namely asp135-->asn and pro85-->ser. both mutations are located in the amino termini domain of xylr, which ... | 1995 | 7890623 |
| identification of functional residues in a 2-hydroxymuconic semialdehyde hydrolase. a new member of the alpha/beta hydrolase-fold family of enzymes which cleaves carbon-carbon bonds. | the 2-hydroxymuconic semialdehyde hydrolase, xylf, of the pseudomonas putida tol plasmid-encoded pathway for the catabolism of toluene and xylenes, catalyzes one of the rarest types of enzyme reaction (ec 3.7.1.9), the hydrolysis of a carbon-carbon bond in its substrate, the ring-fission product of 3-alkyl-substituted catechols. in this study, amino acid sequence comparisons between xylf and other hydrolases, and analysis of the similarity between the predicted secondary structure of xylf and th ... | 1995 | 7890778 |
| analysis of dna bend structure of promoter regulatory regions of xylene-metabolizing genes on the pseudomonas tol plasmid. | the transcription of both the upper operon (op1) coding for m-xylene-degrading enzymes and the positive regulatory gene xyls on the tol plasmid depends on sigma 54-rna polymerase and requires the activator protein xylr that binds to the cis-acting upstream regulatory sequence of each promoter. for transcription of op1 in escherichia coli, integration host factor (ihf) is also required. ihf binds to dna between the upstream regulatory sequence and the promoter sequence of op1. we showed that ihf ... | 1994 | 7896737 |
| substrate specificity of catechol 2,3-dioxygenase encoded by tol plasmid pww0 of pseudomonas putida and its relationship to cell growth. | catechol 2,3-dioxygenase encoded by tol plasmid pww0 of pseudomonas putida consists of four identical subunits, each containing one ferrous ion. the enzyme catalyzes ring cleavage of catechol, 3-methylcatechol, and 4-methylcatechol but shows only weak activity toward 4-ethylcatechol. two mutants of catechol 2,3-dioxygenases (4ecr1 and 4ecr6) able to oxidize 4-ethylcatechol, one mutant (3mcs) which exhibits only weak activity toward 3-methylcatechol but retained the ability to cleave catechol and ... | 1994 | 7928969 |
| transcriptional control of the pseudomonas putida tol plasmid catabolic pathways. | tol plasmid pww0 of pseudomonas putida contains two operons that specify a pathway for the degradation of aromatic hydrocarbons. the upper pathway operon encodes the enzymes for the oxidation of toluene/xylenes to benzoate/toluates, and the metacleavage pathway operon encodes the enzymes for the further oxidation of these compounds to krebs cycle intermediates. their expression is controlled by the gene products of two divergently transcribed regulatory genes, xyir and xyis. the xyir protein, wh ... | 1993 | 7934920 |
| two identical copies of is1246, a 1275 base pair sequence related to other bacterial insertion sequences, enclose the xyl genes on tol plasmid pww0. | two identical direct repeats of a 1275 bp sequence, designated is1246, encompass the xyl genes, which determine the catabolism of toluene, m- and p-xylenes to central metabolites, on the tol catabolic plasmid pww0. is1246 has a terminal inverted repeat of 12 bp (5'gggcacctcgaa3') and contains a major open reading frame of 280 codons. this orf shows significant homology with orfs encoded by a number of bacterial insertion sequences from bacteroides, neisseria and escherichia coli. | 1994 | 7952183 |
| the organization of the pm promoter of the tol plasmid reflects the structure of its cognate activator protein xyls. | the toluate catabolic operon carried by the tol plasmid pww0 of pseudomonas putida is positively regulated by the benzoate-responsive xyls protein which, when activated, stimulates transcription from the operon promoter pm. in this study, the mode in which xyls effects the activity of the pm promoter was examined in vivo by genetic analysis of both protein and promoter variants. substitution of his31asp/ser32pro,leu113pro,phe214leu/glu215a sp/arg216pro or thr312pro, all predicted to disrupt the ... | 1994 | 7969028 |
| loss of the tol meta-cleavage pathway functions of pseudomonas putida strain paw1 (pww0) during growth on toluene. | a derivative of pseudomonas putida strain paw1 bearing the tol plasmid pww0 was isolated from a culture which has grown unlimited on toluene. in contrast to the parent strain paw1, the derivative, strain cg220, is unable to grow with xylenes and toluates, while toluene and benzoate served as substrates. strain cg220 had a remarkable growth advantage against the wild type when grown with toluene. biochemical analysis showed that in strain cg220 toluene was metabolised through the tol plasmid uppe ... | 1994 | 7996396 |
| codon usage patterns suggest independent evolution of two catabolic operons on toluene-degradative plasmid tol pww0 of pseudomonas putida. | tol plasmid pww0 of pseudomonas putida encodes a set of enzymes responsible for the degradation of toluene. the structural genes for these catobolic enzymes are clustered into two operons--namely, the xy/cmab and xy/xyzltegfjqkih operons. we examined the codon usage patterns of these catabolic genes by measuring the codon-usage distances between pairs of these catabolic genes. the codon-usage distance, d, between gene 1 and gene 2 was defined as d = [sigma(pj-qj)2]1/2, are the frequencies of the ... | 1994 | 8007001 |
| transposon-mediated mobilization of chromosomally located catabolic operons of the cam plasmid by tol plasmid transposon tn4652 and cam plasmid transposon tn3614. | the cam (camphor degradation) plasmid is integrated into the chromosome of pseudomonas putida paw-line strains and is not self-transferable as a plasmid via conjugation. our results show that the mobilization of chromosomally located cam and the integration of cam-operons into the chromosome of the new cam+ transconjugants is a reca-independent process mediated by transposons tn4652 (17 kbp) and tn3614 (7.2 kbp). transposon tn3614 is apparently identical to the left-hand and the right-hand seque ... | 1994 | 8012608 |
| functional and structural relationship of various extradiol aromatic ring-cleavage dioxygenases of pseudomonas origin. | the extradiol ring-cleavage dioxygenases derived from seven different pseudomonas strains were expressed in escherichia coli and the substrate specificities were investigated for a variety of catecholic compounds. the substrate range of four 2,3-dihydroxybiphenyl dioxygenases from biphenyl-utilizing bacteria, 3-methylcatechol dioxygenase from toluene utilizing pseudomonas putida f1, 1,2-dihydroxynaphthalene dioxygenase from a nah7 plasmid, and catechol 2,3-dioxygenase from a tol plasmid pww0 wer ... | 1994 | 8020752 |
| chromosomal gene capture mediated by the pseudomonas putida tol catabolic plasmid. | the pseudomonas putida tol plasmid pww0 is able to mediate chromosomal mobilization in the canonical unidirectional way, i.e., from donor to recipient cells, and bidirectionally, i.e., donor-->recipient-->donor (retrotransfer). transconjugants are recipient cells that have received dna from donor cells, whereas retrotransconjugants are donor bacteria that have received dna from a recipient. the tol plasmid pww0 is able to directly mobilize and retromobilize a kanamycin resistance marker integrat ... | 1994 | 8045894 |
| co-regulation by bent dna. functional substitutions of the integration host factor site at sigma 54-dependent promoter pu of the upper-tol operon by intrinsically curved sequences. | the role of integration host factor (ihf) in the regulation of the sigma 54-dependent promoter pu of the tol plasmid of pseudomonas putida has been examined. we have selected in vivo insertions of intrinsically curved dna that restore the responsiveness of an ihf-binding site deletion variant of pu to the cognate activator of the system, xylr. we found five pu derivatives which had inserted a core sequence with 6 phased [a]6 tracts, flanked by different lengths of dna at the location of the form ... | 1994 | 8077217 |
| mineralization of p-methyl-14c-benzoate in soils by pseudomonas putida (pww0). | pseudomonas putida bearing the archetypal tol plasmid pww0 metabolizes p-methylbenzoate through a meta-cleavage pathway. in complex environments such as soils that are relatively rich in organic matter, we observed metabolism of p-methyl-14c-benzoate, which could be monitored as 14co2 evolution from the labelled alkylaromatic. linear 14co2 evolution in soils took place for at least a month, although efficient mineralization of the alkylaromatic required appropriate mass transfer to allow the bac ... | 1993 | 8111534 |
| carbon source-dependent inhibition of xyl operon expression of the pseudomonas putida tol plasmid. | tol plasmid-encoded degradation of benzyl alcohol by pseudomonas putida is inhibited by glucose and other compounds related to the main carbohydrate metabolism in pseudomonas species. we report here that this effect is exerted at the level of expression of the xyl catabolic operons, and two xyl promoters, pu and ps, were identified as the primary targets of this inhibition. xyl promoter activation was also inhibited by glucose in the heterologous escherichia coli system, apparently not however b ... | 1994 | 8132475 |
| genetic evidence for activation of the positive transcriptional regulator xy1r, a member of the ntrc family of regulators, by effector binding. | the xy1r protein positively controls expression from the pseudomonas putida tol plasmid sigma 54-dependent pu and ps promoters, in response to the presence of aromatic effectors such as m-xylene, m-methylbenzyl alcohol, and p-chlorobenzaldehyde in the culture medium. xy1r also autoregulates its own synthesis. a mutant xy1r regulator called xy1r7 was isolated after nitrosoguanidine mutagenesis of the wild-type gene and phenotypic selection for mutants that had acquired the ability to recognize m- ... | 1994 | 8132529 |
| transcriptional induction kinetics from the promoters of the catabolic pathways of tol plasmid pww0 of pseudomonas putida for metabolism of aromatics. | we determined, under several growth conditions, the kinetics of mrna synthesis from the four pseudomonas putida pww0 plasmid promoters involved in degradation of xylenes and methylbenzyl alcohols via toluates. transcription by xyls of the meta-cleavage pathway operon promoter (pm) for the metabolism of alkylbenzoates was stimulated immediately after the addition of an effector, both in luria-bertani (lb) medium and in minimal medium. activation of the sigma 54-dependent upper-pathway operon prom ... | 1994 | 8169200 |
| genetic evidence that the xyls regulator of the pseudomonas tol meta operon controls the pm promoter through weak dna-protein interactions. | the activation of the pm promoter of the meta operon of the tol plasmid of pseudomonas putida by its cognate xyls activator protein in the presence and absence of benzoate inducers has been examined in specialized escherichia coli strains carrying pm-lacz fusions and the xyls gene in different configurations in which all controlling elements are present in near native conditions and stoichometry. expression of a chromosomal pm-xylx::lacz fusion was primarily dependent on the addition of an effec ... | 1994 | 8195070 |
| analysis of the mrna structure of the pseudomonas putida tol meta fission pathway operon around the transcription initiation point, the xylte and the xylfj regions. | the 13 genes encoded by the meta-cleavage operon (approx. 11 kb) of pseudomonas putida tol plasmid pww0 are transcribed from a single promoter, pm. in p. putida, transcription from pm was strictly dependent on the presence of effector-activated xyls protein. three regions of the transcript were analyzed in the wild-type strain of p. putida (pww0) by s1 nuclease protection and primer extension analyses. a major point of transcription initiation was found in the most 5'-end of the operon, which de ... | 1993 | 8241263 |
| the specific growth rate of pseudomonas putida paw1 influences the conjugal transfer rate of the tol plasmid. | the kinetics of the conjugal transfer of a tol plasmid were investigated by using pseudomonas putida paw1 as the donor strain and p. aeruginosa pao 1162 as the recipient strain. short-term batch mating experiments were performed in a nonselective medium, while the evolution of the different cell types was determined by selective plating techniques. the experimental data were analyzed by using a mass action model that describes plasmid transfer kinetics. this method allowed analysis of the mating ... | 1993 | 8250565 |
| new derivatives of tol plasmid pww0. | two new segregants, ppw1-1 and ppw161-1, of pseudomonas putida were isolated from the stock cultures paw85(pww0) and paw85(pww0-161). strain ppw1-1 had lost its ability to grow on m-xylene but was able to grow on m-toluate. a deletion of the left-hand of transposon tn4651, including the upper-operon genes, had taken place in plasmid pww0mut1, isolated from strain ppw1-1. additional deletions were observed in pww0mut1 after 'benzoate-curing' (plasmids pww0mut15, pww0mut19, pww0mut27). the genes o ... | 1993 | 8254307 |
| a substrate-dependent biological containment system for pseudomonas putida based on the escherichia coli gef gene. | a model substrate-dependent suicide system to biologically contain pseudomonas putida kt2440 is reported. the system consists of two elements. one element carries a fusion between a synthetic lac promoter (pa1-04/03) and the gef gene, which encodes a killing function. this element is contained within a transposaseless mini-tn5 transposon so that it can be integrated at random locations on the pseudomonas chromosome. the second element, harbored by plasmid pcc102, is designed to control the first ... | 1993 | 8285679 |
| in vivo reactivation of catechol 2,3-dioxygenase mediated by a chloroplast-type ferredoxin: a bacterial strategy to expand the substrate specificity of aromatic degradative pathways. | the meta-cleavage operon of the tol plasmid pww0 of pseudomonas putida contains 13 genes responsible for the oxidation of benzoate and toluates to krebs cycle intermediates via estradiol (meta) cleavage of (methyl)catechol. the functions of all the genes are known with the exception of xylt. we constructed pww0 mutants defective in the xylt gene, and found that these mutants were not able to grow on p-toluate while they were still capable of growing on benzoate and m-toluate. in the xylt mutants ... | 1993 | 8344270 |
| analysis of pseudomonas gene products using laciq/ptrp-lac plasmids and transposons that confer conditional phenotypes. | novel transposon and plasmid-based broad-host-range expression systems have been developed to facilitate the genetic analysis of gene products of pseudomonas and related gram- bacteria. the properties of laciq/ptrp-lac were used to construct mini-tn5 expression vector transposons and rsf1010-derived plasmids for controlled expression and generation of conditional phenotypes. these plasmids were used to hyper-express the xyls regulator of the meta operon of the tol plasmid of p. putida or the bph ... | 1993 | 8380783 |
| construction of a pseudomonas hybrid strain that mineralizes 2,4,6-trinitrotoluene. | a bacterium, pseudomonas sp. strain c1s1, able to grow on 2,4,6-trinitrotoluene (tnt), 2,4- and 2,6-dinitrotoluene, and 2-nitrotoluene as n sources, was isolated. the bacterium grew at 30 degrees c with fructose as a c source and accumulated nitrite. through batch culture enrichment, we isolated a derivative strain, called pseudomonas sp. clone a, which grew faster on tnt and did not accumulate nitrite in the culture medium. use of tnt by these two strains as an n source involved the successive ... | 1993 | 8468288 |
| a comparison of the multiple alleles of xyls carried by tol plasmids pww53 and pdk1 and its implications for their evolutionary relationship. | both of the independently isolated tol plasmids pww53 and pdk1 contain multiple regions homologous to the xyls regulatory gene of the archetypal tol plasmid pww0. the three homologues on pww53 vary in the extent of their homology to xylspww0, xyls1pww53 is 99% identical to xylspww0 and is located relative to the single copy of xylrpww53 in exactly the same way as xyls and xylr on pww0. the dna sequence of xyls3pww53 is 87% identical to the xylspww0 sequence within the coding region but the non-c ... | 1993 | 8473862 |
| identification of a cis-acting sequence within the pm promoter of the tol plasmid which confers xyls-mediated responsiveness to substituted benzoates. | the dna sequences within the pm promoter/operator region of the meta operon of the tol plasmid of pseudomonas putida, which confer xyls-mediated responsiveness to substituted benzoates, have been identified through deletion analysis and mutagenesis of the region. integrity and proper phasing of two homologous tandem sequences 5'-tgcaapuaapu-pyggnta-3', separated by six base-pairs and overlapping with the -35 region of the pm promoter, was essential for m-toluate activation of a pm-lacz fusion in ... | 1993 | 8478926 |
| kinetic studies on benzyl alcohol dehydrogenase encoded by tol plasmid pwwo. a member of the zinc-containing long chain alcohol dehydrogenase family. | the nucleotide sequence of the structural gene for benzyl alcohol dehydrogenase encoded by tol plasmid pwwo of pseudomonas putida has been determined. benzyl alcohol dehydrogenase is a member of the long-chain zinc alcohol dehydrogenase family and, like other alcohol dehydrogenases of this family, contains two zinc atoms per subunit. benzyl alcohol dehydrogenase, while sharing 31% identical residues with horse liver alcohol dehydrogenase, contains several amino acid substitutions near the active ... | 1993 | 8496150 |
| physical organization of the upper pathway operon promoter of the pseudomonas tol plasmid. sequence and positional requirements for xylr-dependent activation of transcription. | the upper pathway operon of the pseudomonas putida tol plasmid belongs to the -12/-24 class of promoters. these promoters exhibit three regions critical for regulated transcription, namely, the -12/-24 site for rna polymerase/sigma 54 binding, the -55/-67 region for ihf protein binding, and the -130(uas2)/-170(uas1) region, where two sites for xylr binding are located. the xylr-protected g residues located at -131, -139, -160 and -169 were replaced with as, and the activity of the mutant promote ... | 1993 | 8510657 |
| comparison of the nucleotide sequences of the meta-cleavage pathway genes of tol plasmid pww0 from pseudomonas putida with other meta-cleavage genes suggests that both single and multiple nucleotide substitutions contribute to enzyme evolution. | tol plasmid pww0 from pseudomonas putida mt-2 encodes catabolic enzymes required for the oxidation of toluene and xylenes. the structural genes for these catabolic enzymes are clustered into two operons, the xylcmabn operon, which encodes a set of enzymes required for the transformation of toluene/xylenes to benzoate/toluates, and the xylxyzltegfjqkih operon, which encodes a set of enzymes required for the transformation of benzoate/toluates to krebs cycle intermediates. the latter operon can be ... | 1993 | 8510667 |
| identification of the repressor subdomain within the signal reception module of the prokaryotic enhancer-binding protein xylr of pseudomonas putida. | in the presence of m-xylene, the protein xylr encoded by the tol plasmid of pseudomonas putida, activates the final sigma54-dependent promoter pu. early activation stages involve the release of the intramolecular repression caused by the signal reception n-terminal (a domain) of xylr on the central module of the protein. a genetic approach has been followed to locate the specific segment within a domain of xylr that is directly responsible for its down-regulation in the absence of inducer, as co ... | 1996 | 8626467 |
| catechol 2,3-dioxygenases functional in oxygen-limited (hypoxic) environments. | we studied the degradation of toluene for bacteria isolated from hypoxic (i.e., oxygen-limited) petroleum-contaminated aquifers and compared such strains with other toluene degraders. three pseudomonas isolates, p. pickettii pko1, pseudomonas sp. strain w31, and p. fluorescens cfs215, grew on toluene when nitrate was present as an alternate electron acceptor in hypoxic environments. we examined kinetic parameters (k(m) and vmax) for catechol 2,3-dioxygenase (c230), a key shared enzyme of the tol ... | 1996 | 8633871 |
| expression of the tol plasmid xyls gene in pseudomonas putida occurs from a alpha 70-dependent promoter or from alpha 70- and alpha 54-dependent tandem promoters according to the compound used for growth. | growth of pseudomonas putida (pwwo) on alkylbenzoates requires the expression of the meta pathway operon, which is mediated by the xyls protein after binding of a benzoate effector. alternatively, in cells growing on toluene or its aromatic alcohols, overexpression of xyls mediated by xylr activated by these compounds leads to overproduction of the xyls regulator, which even in the absence of benzoate effectors stimulates transcription from the meta cleavage pathway operon promoter. we show here ... | 1996 | 8636038 |
| physical and functional analysis of the prokaryotic enhancer of the sigma 54-promoters of the tol plasmid of pseudomonas putida. | the physical and the functional organization of the upstream cis-acting sequence that controls at a distance the transcriptional activity of pu and ps, the two sigma 54-dependent promoters of the tol (toluene/xylene biodegradation) operons of pseudomonas putida, have been determined. dnase i and hydroxyl radical footprinting of the promoters with the purified and pre-activated enhancer-binding protein xylr clearly indicated the presence of two distinct binding sites (proximal and distal) that we ... | 1996 | 8636992 |
| untranslated sequence upstream of mara in the multiple antibiotic resistance locus of escherichia coli is related to the effector-binding domain of the xyls transcriptional activator. | mara, the 129-amino-acid (aa) protein which plays a crucial role in the multiple antibiotic resistance (mar) phenotype in escherichia coli, shows homology to members of the xyls/arac family of transcriptional regulators. although these proteins vary in size from around 100 to 350 aa they all contain a dna-binding domain with a helix-turn-helix motif. the larger ones, e.g., xyls, arac, and rob, contain an additional domain either at their amino- or at their carboxyterminus. this domain is importa ... | 1996 | 8642609 |
| vtr expression cassettes for engineering conditional phenotypes in pseudomonas: activity of the pu promoter of the tol plasmid under limiting concentrations of the xylr activator protein. | a simplified procedure to construct recombinant pseudomonas putida (pp) and related bacteria, which transcribe conditionally specific genes inserted into their chromosome in response to lac inducers such as iptg, has been developed. the method is based on the so-called vtr expression cassettes. these are three small (1.98-kb) dna segments engineered as noti restriction fragments that include a laciq gene along with the hybrid trp/lac promoter, ptrc, followed by an optimised translation initiatio ... | 1996 | 8654996 |
| bacterial plasmid conjugation on semi-solid surfaces monitored with the green fluorescent protein (gfp) from aequorea victoria as a marker. | horizontal transfer of the tol plasmid was examined in pseudomonas putida (pp) kt2442 micro-colonies on semi-solid agar surfaces. horizontal gene transfer is usually studied in large populations where all information is based on average estimates of the transfer events in the entire population. we have used the green fluorescent protein (gfp) from the jellyfish aequorea victoria as a plasmid marker, in combination with single-cell observations. this provided hitherto unknown details on the distr ... | 1996 | 8707058 |
| structure of catechol 2,3-dioxygenase gene encoded in chromosomal dna of pseudomonas putida kf715. | a catechol 2,3-dioxygenase gene in chromosomal dna of p. putida kf715 was cloned and its nucleotide sequence analyzed. the enzyme gene was composed of 924 base pairs with atg initiation codon and tga termination codon, which can encode a polypeptide of molecular weight 35 kda containing 307 amino acids. a promoter-like sequence and a ribosome-binding sequence were identified upstream the enzyme gene. a deduced amino acid sequence of the catechol 2,3-dioxygenase exhibited 94% identity with that o ... | 1996 | 8713131 |
| tol plasmid transcription factor xyls binds specifically to the pm operator sequence. | xyls, an arac family transcription factor, positively regulates transcription of pseudomonas putida tol plasmid meta operon from the pm promoter. a tandem of 15 bp homologous direct repeats, separated by 6 bp and overlapping with the -35 hexamer of the promoter, is required for the activation of pm by xyls in vivo. in this study we have characterized specific binding of xyls to the pm operator om. xyls was overexpressed with an epitope tag in its n-terminus. tagged xyls (n-xyls) was immunopurifi ... | 1996 | 8736536 |