| a bacterial peptide acting as a plant nuclear targeting signal: the amino-terminal portion of agrobacterium vird2 protein directs a beta-galactosidase fusion protein into tobacco nuclei. | agrobacterium tumefaciens is a soil bacterium capable of transferring dna to the genome of higher plants. of the virulence region-encoded proteins of the tumor-inducing (ti) plasmid of a. tumefaciens, the vird1 and vird2 proteins are essential for t-dna transfer to plant cells. these two proteins have been shown to be directly responsible for the formation of t-strands. vird2 was also shown to be firmly attached to the 5' termini of t-strands; these facts have led to its postulation as a pilot p ... | 1990 | 2124696 |
| iaa synthesis and root induction with iaa genes under heat shock promoter control. | we have devised a heat shock-inducible indole-3-acetic acid (iaa) synthesis system for plant cells, which is based on the iaa genes of the agrobacterium tumefaciens t-dna and the heat shock promoter hsp70 of drosophila melanogaster. two dna constructs were tested: one contains the iaam gene linked to the hsp70 promoter (hsp70-iaam) and encodes the production of indoleacetamide (iam), the other contains hsp70-iaam and the wild-type iaah gene which codes for the conversion of iam into iaa (hsp70-i ... | 1990 | 2129423 |
| synthesis and self-assembly of a functional monoclonal antibody in transgenic nicotiana tabacum. | immunoglobulin light and heavy chains are synthesized in mammalian cells as precursors containing a signal peptide. processing and assembling result in formation of active antibodies. chimeric genes have been made containing the coding sequence of the barley alpha-amylase signal peptide which has been fused to cdnas coding for either the mature light or the mature heavy chain of a monoclonal antibody. a plasmid was constructed linking both chimeric genes under the control of plant active promote ... | 1990 | 2129424 |
| structure and function of the promoter of the carrot v-type h(+)-atpase catalytic subunit gene. | we investigated the 5'-upstream region of the gene encoding the catalytic subunit of the v-type h(+)-atpase in daucus carota. a genomic sublibrary was screened with a cdna probe, and a 4-kilobase genomic clone was obtained covering the first two exons and about 3 kilobases of the 5'-upstream sequence. the intron/exon boundaries matched established consensus sequences. within 240 base pairs (bp) upstream of the initiation codon three putative tata boxes were found. ribonuclease protection and pri ... | 1990 | 2139875 |
| a family of atpases involved in active partitioning of diverse bacterial plasmids. | low copy-number bacterial plasmids f (the classical escherichia coli sex factor) and prophage p1 encode partitioning functions which may provide fundamental insights into the active processes which ensure that bacterial genomes are segregated to both daughter cells prior to cell division. these partitioning systems involve two proteins: para and parb. we report that incc from the broad host-range plasmid rk2 is a member of the family of para partitioning proteins and that these proteins (as well ... | 1990 | 2149583 |
| homologous recombination in plant cells after agrobacterium-mediated transformation. | a single amino-acid change in the acetolactate synthase (als) protein of tobacco confers resistance to the herbicide chlorsulfuron. a deleted, nonfunctional fragment from the acetolactate synthase gene, carrying the mutant site specifying chlorsulfuron resistance plus a closely linked novel restriction site marker, was cloned into a binary vector. tobacco protoplasts transformed with agrobacterium tumefaciens carrying this vector yielded chlorsulfuron-resistant colonies. dna gel blot analysis of ... | 1990 | 2152167 |
| vir genes influence conjugal transfer of the ti plasmid of agrobacterium tumefaciens. | mutation of the genes vira, virb, virc, and virg of the agrobacterium tumefaciens octopine-type ti plasmid ptir10 was found to cause a 100- to 10,000-fold decrease in the frequency of conjugal transfer of this plasmid between agrobacterium cells. this effect was not absolute, however, in that it occurred only during early times (18 to 24 h) of induction of the conjugal transfer apparatus by octopine. induction of these mutant agrobacterium strains by octopine for longer periods (48 to 72 h) resu ... | 1990 | 2155206 |
| a chromosomal agrobacterium tumefaciens gene required for effective plant signal transduction. | the vir gene products of agrobacterium tumefaciens carry out the transfer of t-dna to the plant genome. effective transcriptional induction of the vir genes by plant signal molecules is controlled by two vir gene products, vira and virg. in this study we have identified and cloned a chromosomal region which is also required for vir gene induction. transposon insertions within this region reduce induction significantly and strongly attenuate virulence, resulting in a restricted host range for inf ... | 1990 | 2156804 |
| overexpression of vird1 and vird2 genes in agrobacterium tumefaciens enhances t-complex formation and plant transformation. | the vird1 and vird2 proteins encoded by an inducible locus of the virulence (vir) region of the agrobacterium tumefaciens ti plasmid are required for site-specific nicking at t-dna border sites. we have determined the nucleotide sequence of a 3.6-kilobase-pair fragment carrying the vird locus from nopaline ti plasmid ptic58. in contrast to the previous report (hagiya et al., proc. natl. acad. sci. usa 82:2669-2673, 1985), we found that the first three open reading frames were capable of encoding ... | 1990 | 2165478 |
| efficient transformation of agrobacterium tumefaciens by electroporation. | high-voltage electroporation was used to transform agrobacterium tumefaciens strains a136 and a348, reaching the efficiency of 1-3 x 10(8) transformants/micrograms dna. transformation frequency was dependent on the electrical field strength and the pulse length. no significant reduction in transformation efficiency was observed when the transforming dna contained sites sensitive to endonuclease atuci of a. tumefaciens. | 1990 | 2165971 |
| pica, a novel plant-inducible locus on the agrobacterium tumefaciens chromosome. | we used the transposon mu di1681 to identify genes on the agrobacterium tumefaciens chromosome that are inducible by extracts from carrot roots. one such locus (pica, for plant inducible chromosomal), harbored by a. tumefaciens at156, was inducible 10- to 50-fold by these extracts. mutation of pica had no detectable effect upon bacterial growth or virulence under laboratory assay conditions. however, a. tumefaciens cells harboring a mutated pica locus aggregated into long "ropes" when incubated ... | 1990 | 2170328 |
| enterobactin-mediated iron transport in pseudomonas aeruginosa. | a pyoverdine-deficient strain of pseudomonas aeruginosa was unable to grow in an iron-deficient minimal medium in the presence of the nonmetabolizable iron chelator ethylene diamine-di(omega-hydroxyphenol acetic acid) (eddha), although addition of enterobactin to eddha-containing minimal media did restore growth of the pyoverdine-deficient p. aeruginosa. consistent with the apparent ability of enterobactin to provide iron to p. aeruginosa, enterobactin-dependent 55fe3+ uptake was observed in cel ... | 1990 | 2174865 |
| evidence that modulation requires sequences downstream of the promoters of two vir-repressed genes of bordetella pertussis. | gene expression in bordetella pertussis is altered by environmental signals in a process called antigenic modulation. in the presence of modulating signals, expression of several known virulence factors and outer membrane proteins is coordinately reduced. from a bank of tnphoa fusions, we have identified five genes whose expression profiles are reciprocal of those of the major virulence determinants; that is, alkaline phosphatase activity is maximal during growth in the presence of the modulator ... | 1990 | 2174866 |
| excision of a ds-like maize transposable element (ac delta) in a transient assay in petunia is enhanced by a truncated coding region of the transposable element ac. | the excision of a ds-like transposable element (ac delta) is mediated in trans by the transposable element ac or its derivatives in petunia protoplasts cotransfected with two plasmid dnas. excision restores the activity of the beta-glucuronidase (gus) gene that is otherwise shut off by the presence of ac delta in its leader sequence. a transient expression assay (histochemical test) is used to detect the beta-glucuronidase activity at the protoplast to detect the beta-glucuronidase activity at t ... | 1990 | 2177522 |
| plant chromosome/marker gene fusion assay for study of normal and truncated t-dna integration events. | during agrobacterium tumefaciens infection, the t-dna flanked by 24 bp imperfect direct repeats is transferred and stably integrated into the plant chromosome at random positions. here we measured the frequency with which a promoterless reporter gene is activated after insertion into the nicotiana tabacum sr1 genome. when adjacent to the right or left t-dna border sequences, at least 35% of the transformants express the marker gene, suggesting preferential t-dna insertion (greater than 70%) in t ... | 1990 | 2177527 |
| transcriptional induction of an agrobacterium regulatory gene at tandem promoters by plant-released phenolic compounds, phosphate starvation, and acidic growth media. | transcription of the virg gene of agrobacterium tumefaciens was previously shown to be expressed from two tandem promoters and to be responsive to three stimuli: plant-released phenolic compounds, phosphate starvation, and acidic media. in this report, i describe a set of deletions and other alterations of the 5' end of virg that show that the upstream promoter (p1) is necessary for induction by phenolic compounds and by phosphate starvation, whereas the downstream promoter (p2) is induced by ac ... | 1990 | 2185220 |
| characteristics of the nopaline catabolic plasmid in agrobacterium strains k84 and k1026 used for biological control of crown gall disease. | wild-type agrobacterium radiobacter strain 84 and its tra- derivative k1026, used for biological control of crown gall disease, each contain the plasmid patk84b. it confers incompatibility to tumor-inducing (ti) plasmids of pathogenic a. tumefaciens, thus preventing transfer of ti plasmids into k84 and k1026, and the consequent development of pathogens resistant to the specific antibiotic, agrocin 84 produced by k84 and k1026. patk84b also resembles one group of ti plasmids in its capacity for d ... | 1990 | 2194227 |
| molecular characterization of the vir regulon of agrobacterium tumefaciens: complete nucleotide sequence and gene organization of the 28.63-kbp regulon cloned as a single unit. | the entire vir regulon of agrobacterium tumefaciens was subcloned and the complete 28.6-kbp nucleotide sequence was determined. the regulon was cloned as a single unit into two replicons, one of which replicates at a high copy number in this bacterium, and a second which has broad-host-range features to replicate in other gram-negative bacteria. these vir region plasmids are able to confer in trans the processing and transfer activities on a second plasmid containing the t-dna. in the high copy ... | 1990 | 2194232 |
| in vitro activity of ljc10,627, a new carbapenem antibiotic with high stability to dehydropeptidase i. | the in vitro activity of ljc10,627, a new carbapenem, was compared with those of imipenem and ceftazidime. ljc10,627 had broad-spectrum activity against gram-positive and gram-negative clinical isolates. the mics of this compound for 90% of members of the family enterobacteriaceae tested (mic90s), including strains resistant to ceftazidime, ranged from 0.1 to 25 micrograms/ml. ljc10,627 inhibited pseudomonas aeruginosa at an mic90 of 3.13 micrograms/ml; it thus was twofold more active than imipe ... | 1990 | 2203313 |
| complementation analysis of agrobacterium tumefaciens ti plasmid virb genes by use of a vir promoter expression vector: virb9, virb10, and virb11 are essential virulence genes. | the virb gene products of the agrobacterium tumefaciens tumor-inducing (ti) plasmid have been proposed to mediate t-dna transport through the bacterial cell wall into plant cells. previous genetic analysis of the approximately 9.5-kilobase-pair virb operon has been limited to transposon insertion mutagenesis. due to the polarity of the transposon insertions, only the last gene in the operon, virb11, is known to provide an essential virulence function. we have now begun to assess the contribution ... | 1990 | 2203743 |
| extrachromosomal homologous recombination and gene targeting in plant cells after agrobacterium mediated transformation. | we determined whether t-dna molecules introduced into plant cells using agrobacterium are suitable substrates for homologous recombination. for the detection of such recombination events different mutant versions of a nptii construct were used. in a first set of experiments protoplasts of nicotiana tabacum sr1 were cocultivated with two agrobacterium tumefaciens strains. each strain contained a different t-dna, one carrying a 5' deleted nptii gene and the other a nptii gene with a 3' deletion. a ... | 1990 | 2209538 |
| inhibition by agrobacterium tumefaciens and pseudomonas savastanoi of development of the hypersensitive response elicited by pseudomonas syringae pv. phaseolicola. | injection into tobacco leaves of biotype 1 agrobacterium tumefaciens or of pseudomonas savastanoi inhibited the development of a visible hypersensitive response to the subsequent injection at the same site of pseudomonas syringae pv. phaseolicola. this interference with the hypersensitive response was not seen with injection of bacterial growth medium or escherichia coli cells. live a. tumefaciens cells were required for the inhibitory effect. various mutants and strains of a. tumefaciens were e ... | 1990 | 2211508 |
| genetic and sequence analysis of an 8.7-kilobase pseudomonas denitrificans fragment carrying eight genes involved in transformation of precorrin-2 to cobyrinic acid. | a 8.7-kilobase dna fragment carrying pseudomonas denitrificans cob genes has been sequenced. the nucleotide sequence and the genetic analysis revealed that this fragment carries eight different cob genes (cobf to cobm). six of these genes have the characteristics of translationally coupled genes. cobi has been identified as s-adenosyl-l-methionine (sam):precorrin-2 methyltransferase structural gene because the encoded protein has the same nh2 terminus and molecular weight as those of the purifie ... | 1990 | 2211521 |
| mutational analysis of the virg protein, a transcriptional activator of agrobacterium tumefaciens virulence genes. | the virg protein of agrobacterium tumefaciens is required in conjunction with the vira protein for transcriptional activation of the virulence (vir) genes in response to plant phenolic compounds. these proteins are members of a family of two component regulatory systems. vir genes are activated via a cascade of phosphorylation reactions involving a specific aspartic acid residue of the virg protein. we have conducted a mutational analysis of the virg protein. by mutating conserved and nonconserv ... | 1990 | 2211523 |
| transgenic nicotiana debneyii expressing viral coat protein are resistant to potato virus s infection. | the coat protein gene from potato virus s (pvs) was introduced into nicotiana debneyii by leaf disc transformation using agrobacterium tumefaciens. transgenic plants expressing the viral coat protein were highly resistant to subsequent infection by the me strain of pvs as indicated by an absence of symptom development and a lack of accumulation of virus in both the inoculated and upper leaves. as in reported experiments with plants expressing potato virus x coat protein, plants expressing pvs co ... | 1990 | 2212996 |
| physical map and properties of a 90-mda plasmid of azospirillum brasilense sp7. | homology was previously detected between the dna restriction fragments containing rhizobium meliloti nodulation genes and the 90-mda plasmid, p90, of azospirillum brasilense sp7. two dna loci from sp7 genome that complement mutations in the exopolysaccharide synthesis genes, exob and exoc, of r. meliloti were also shown to be present on the plasmid. a more detailed characterization of the plasmid was undertaken to establish its physical map and to localize the nod homologies and other specific r ... | 1990 | 2217570 |
| isolation of the replication dna region from a rhizobium plasmid and examination of its potential as a replicon for rhizobiaceae cloning vectors. | the dna region essential for replication and stability of a native plasmid (ptm5) from rhizobium sp. (hedysarum) has been identified and isolated within a 5.4-kb psti restriction fragment. the isolation of this region was accomplished by cloning endonuclease-restricted ptm5 dna into a cole1-type replicon and selecting the recombinant plasmids containing the ptm5 replicator (ptm5 derivative plasmids) by their ability to replicate in rhizobium. dna homology studies revealed that ptm5-like replicon ... | 1990 | 2217572 |
| [uvrd-like sequences in the genome of agrobacterium tumefaciens]. | | 1990 | 2227394 |
| agrobacterium rhizogenes mutants that fail to bind to plant cells. | transposon insertion mutants of agrobacterium rhizogenes were screened to obtain mutant bacteria that failed to bind to carrot suspension culture cells. a light microscope binding assay was used. the bacterial isolates that were reduced in binding to carrot cells were all avirulent on bryophyllum diagremontiana leaves and on carrot root disks. the mutants did not appear to be altered in cellulose production. the composition of the medium affected the ability of the parent and mutant bacteria to ... | 1990 | 2228955 |
| characterization of the virb operon of an agrobacterium tumefaciens ti plasmid: nucleotide sequence and protein analysis. | the virulence regulon of the agrobacterium tumefaciens tic58 plasmid is composed of six operons, vira, virb, virg, virc, vird and vire, which direct the transfer of t-dna into plant cells. the 9.5 kbp virb operon is the largest of these operons and its entire nucleotide sequence was determined and found to contain eleven open reading frames (orfs). gene fusions of each virb orf to t7 phi 10 were made and overexpressed in escherichia coli to confirm that they encode proteins of predicted size. hy ... | 1990 | 2233252 |
| [new shuttle-type vectors for cloning in escherichia coli and agrobacterium tumefaciens]. | the vectors capable of replication in escherichia coli and agrobacterium tumefaciens have been constructed on the basis of the plasmid pub5502. the constructed vectors pva12, pva12-2, pva12-4 contain the mini-replicon and trimethoprim resistance gene (tp) of a broad host-range plasmid r388 (incw). the pva12 vector (8.8 kb) has been constructed by insertion of a kanamycin resistance gene (km) from the plasmid puc-4k into a psti site. it possesses 7 unique restriction sites for xhoi, smai, pvui, p ... | 1990 | 2233784 |
| enhancer sequences from arabidopsis thaliana obtained by library transformation of nicotiana tabacum. | in this paper we report on the use of a bidirectional enhancer cloning vehicle to isolate and characterize new enhancer sequences from arabidopsis thaliana. a library of a. thaliana genomic sau3a segments was constructed in escherichia coli in the binary plasmid enhancer cloning vehicle proa97. the t-dna based vector carries abbreviated tata regions from the cauliflower mosaic virus 35s transcription unit upstream of two genes. the library was transferred via triparental mating into agrobacteriu ... | 1990 | 2250645 |
| purification, cloning, and primary structure of an enantiomer-selective amidase from brevibacterium sp. strain r312: structural evidence for genetic coupling with nitrile hydratase. | an enantiomer-selective amidase active on several 2-aryl and 2-aryloxy propionamides was identified and purified from brevibacterium sp. strain r312. oligonucleotide probes were designed from limited peptide sequence information and were used to clone the corresponding gene, named amda. highly significant homologies were found at the amino acid level between the deduced sequence of the enantiomer-selective amidase and the sequences of known amidases such as indoleacetamide hydrolases from pseudo ... | 1990 | 2254253 |
| osmoregulation in agrobacterium tumefaciens: accumulation of a novel disaccharide is controlled by osmotic strength and glycine betaine. | we have investigated the mechanism of osmotic stress adaptation (osmoregulation) in agrobacterium tumefaciens biotype i (salt-tolerant) and biotype ii (salt-sensitive) strains. using natural-abundance 13c nuclear magnetic resonance spectroscopy, we identified all organic solutes that accumulated to significant levels in osmotically stressed cultures. when stressed, biotype i strains (c58, nt1, and a348) accumulated glutamate and a novel disaccharide, beta-fructofuranosyl-alpha-mannopyranoside, c ... | 1990 | 2254260 |
| agrobacterium tumefaciens t-dna gene 6b stimulates rol-induced root formation, permits growth at high auxin concentrations and increases root size. | all agrobacterium tumefaciens strains studied up to now transfer an active 6b gene to plant cells. however, the role of this gene in natural tumour induction is unknown. various effects of 6b on plant cell growth have been described, but the precise mechanism by which 6b causes these effects has not been elucidated. earlier experiments indicated that the 6b gene might increase auxin sensitivity as do the a. rhizogenes rol genes. the 6b gene from tm4 (t-6b) was therefore compared with the rolb an ... | 1990 | 2259331 |
| characterization of the virg binding site of agrobacterium tumefaciens. | expression of agrobacterium tumefaciens virulence (vir) genes is dependent on the presence of a conserved 'vir box' sequence in their 5' nontranscribed regions. the location and number of these sequences vary considerably in different vir genes. site-directed mutagenesis was used to identify the functional vir box(es) of virb, virc and vird. for virb expression both vir box b1 and b2 are required but only the vir box b1 is absolutely essential. of the five vir boxes of virc and vird two are requ ... | 1990 | 2263453 |
| vird2 gene product from the nopaline plasmid ptic58 has at least two activities required for virulence. | virulence genes vird1 and vird2 are required for t-dna processing in agrobacterium tumefaciens. the regions within vird2 contributing to t-dna processing and virulence were investigated. some insertional mutations in vird2 prevented t-dna border endonucleolytic cleavage and produced an avirulent phenotype. however, a non-polar insertion immediately after bp 684 of the 1344 bp open reading frame of vird2 did not inhibit endonucleolytic cleavage but still caused a loss of virulence. this suggested ... | 1990 | 2263456 |
| agrobacterium plasmids encode structurally and functionally different loci for catabolism of agrocinopine-type opines. | agrobacterium tumefaciens strains c58, t37, k827 and j73, a. rhizogenes strains a4 and 15834, and a. radiobacter strain k299 were all susceptible to agrocin 84 and this sensitivity was enhanced in each case by addition of agrocinopines a and b. analysis of transconjugants showed that sensitivity of strain a4 to agrocin 84 was encoded by para4a and not by the rhizogenic plasmid, pria4. the acc region of the a. tumefaciens nopaline-type ti plasmid ptic58, contained on the recombinant plasmid pthh2 ... | 1990 | 2270086 |
| identification and quantitation of corrinoid precursors of cobalamin from pseudomonas denitrificans by high-performance liquid chromatography. | after initial pretreatment for removal of interfering substances, corrinoid precursors of cobalamin from cultures of pseudomonas denitrificans were separated by hplc with a gradient elution system. in this system, all the following compounds are separated in their dicyano form, and retention times are given: cobyrinic acid; cobyrinic acid a-amide; cobyrinic acid c-amide; cobyrinic acid g-amide; cobyrinic acid a,g-diamide; cobyrinic acid c,g-diamide; cobyrinic acid a,c-diamide; cobyrinic acid a,c ... | 1990 | 2278386 |
| involvement of azospirillum brasilense plasmid dna in the production of indole acetic acid. | indole acetic acid (iaa) production in azospirillum brasilense strain sp245 is controlled by a 85 mda plasmid naturally present in this bacterium. in the presence of l-tryptophan, anthranilic acid production and almost no iaa production occurs in a derivative strain harbouring a tn5-mob insertion in the 85 mda plasmid. agrobacterium tumefaciens strain gm19023, upon transfer of tn5-mob labelled 85 mda plasmid of a. brasilense sp245, gains the ability to produce anthranilic acid. | 1990 | 2283026 |
| virg, an agrobacterium tumefaciens transcriptional activator, initiates translation at a uug codon and is a sequence-specific dna-binding protein. | the agrobacterium tumefaciens ti plasmid virg locus, in conjunction with vira and acetosyringone, activates transcription of the virulence (vir) genes. insertional and deoxyoligonucleotide-directed mutagenesis studies showed that both octopine and nopaline ti plasmid virg genes initiate translation at a uug codon. virg protein initiated at this uug codon was found to be 241 amino acid residues in length and had an apparent molecular mass of 27.1 kilodaltons. a salmonella typhimurium trp-virg tra ... | 1990 | 2307647 |
| biochemical characterization of avirulent exoc mutants of agrobacterium tumefaciens. | the synthesis of periplasmic beta(1-2)glucan is required for crown gall tumor formation by agrobacterium tumefaciens and for effective nodulation of alfalfa by rhizobium meliloti. the exoc (psca) gene is required for this synthesis by both bacteria as well as for the synthesis of capsular polysaccharide and normal lipopolysaccharide. we tested the possibility that the pleiotropic exoc phenotype is due to a defect in the synthesis of an intermediate common to several polysaccharide biosynthetic p ... | 1990 | 2307661 |
| correction: characterization of the virb operon from agrobacterium tumefaciens ti plasmid. | | 1990 | 2307685 |
| binding-protein-dependent lactose transport in agrobacterium radiobacter. | agrobacterium radiobacter ncib 11883 was grown in lactose-limited continuous culture at a dilution rate of 0.045/h. washed cells transported [14c]lactose and [methyl-14c]beta-d-thiogalactoside, a nonmetabolisable analog of lactose, at similar rates and with similar affinities (km for transport, less than 1 microm). transport was inhibited to various extents by the uncoupling agent carbonyl cyanide p-trifluoromethoxyphenylhydrazone, by unlabeled beta-galactosides and d-galactose, and by osmotic s ... | 1990 | 2318800 |
| osmosensitivity phenotypes of agrobacterium tumefaciens mutants that lack periplasmic beta-1,2-glucan. | the periplasmic cyclic beta-1,2-glucan of agrobacterium tumefaciens is believed to maintain high osmolarity in the periplasm during growth of the bacteria on low-osmotic-strength media. strains with mutations in the chva or chvb gene do not accumulate beta-1,2-glucan in their periplasm and exhibit pleiotropic phenotypes, including inability to form crown gall tumors on plants. we examined the effects of medium osmolarity to determine whether some or all of these phenotypes result from suboptimal ... | 1990 | 2318812 |
| virulence genes promote conjugative transfer of the ti plasmid between agrobacterium strains. | certain virulence region operons of the agrobacterium tumefaciens ti plasmid promoted conjugative ti plasmid transfer. mutations in the vir region of ptic58 inhibited conjugative plasmid transfer between a. tumefaciens strains. mutations in vira, virg, 5' virb, and vire had the greatest effect on plasmid transfer, and mutations in virc had no effect. transfer inhibition in vir mutants occurred in the presence or absence of acetosyringone. | 1990 | 2318813 |
| re-examination of cellular cyclic beta-1,2-glucans of rhizobiaceae: distribution of ring sizes and degrees of glycerol-1-phosphate substitution. | gel-filtration and thin layer chromatography of low molecular weight carbohydrates from culture filtrates of agrobacterium radiobacter, isolate ii, have shown, that next to the neutral beta-1,2-glucan fraction a major acidic fraction was present which was found to be glycerophosphorylated cyclic beta-1,2-glucans. re-examination of cyclic beta-1,2-glucan preparations which had been obtained by extraction of rhizobium cells with hot phenol-water also showed these acidic modified beta-1,2-glucans t ... | 1990 | 2321938 |
| construction of an intron-containing marker gene: splicing of the intron in transgenic plants and its use in monitoring early events in agrobacterium-mediated plant transformation. | agrobacterium tumefaciens is a commonly used tool for transforming dicotyledonous plants. the underlying mechanism of transformation however is not very well understood. one problem complicating the analysis of this mechanism is the fact that most indicator genes are already active in agrobacterium, thereby preventing the precise determination of timing and localisation of t-dna transfer to plant cells. in order to overcome this obstacle a modified prokaryotic indicator gene was constructed. the ... | 1990 | 2325623 |
| expression of the agrobacterium tumefaciens chvb virulence region in azospirillum spp. | inner membranes of azospirillum brasilense incubated with udp-glucose were unable to synthesize beta-(1-2) glucan and lacked the 235-kilodalton intermediate protein known to be involved in the synthesis of beta-(1-2) glucan in agrobacterium tumefaciens and rhizobium meliloti. inner membranes of a. brasilense strains carrying a cosmid containing the chromosomal virulence genes chva and chvb of agrobacterium tumefaciens formed beta-(1-2) glucan in vitro and synthesized the 235-kilodalton intermedi ... | 1990 | 2332404 |
| in vitro antibacterial activities of three plants used in traditional medicine in sierra leone. | the antibacterial activities of the methanol and hot and cold aqueous extracts of the leaves of aspilia africana, ficus exasperata and mareya micrantha were bioassayed against three gram-negative and three gram-positive bacterial species: aerobacter aerogenes, agrobacterium tumefaciens, bacillus subtilis, clostridium sporogenes, escherichia coli and staphylococcus aureus. the methanol and aqueous extracts of the leaves of aspilia africana and mareya micrantha and the undiluted oil of m. micranth ... | 1990 | 2335960 |
| plant nuclear factor asf-1 binds to an essential region of the nopaline synthase promoter. | we have characterized a tobacco nuclear factor that binds to the -118 region of the nopaline synthase (nos) promoter from the ti plasmid of agrobacterium tumefaciens. the binding site for this factor, identified by dnase i footprinting, encompasses the region from -138 to -103 of the nos promoter. this region, which contains a potential z-dna-forming sequence, was previously shown to be essential for nos promoter activity in transgenic tobacco. a synthetic 21-base pair sequence from the protecte ... | 1990 | 2351681 |
| the virb operon of agrobacterium tumefaciens ptic58 encodes 11 open reading frames. | agrobacterium tumefaciens genetically transforms plant cells by transferring a copy of its t-dna to the plant where it is integrated and stably maintained. in the presence of wounded plant cells this process is activated and mediated by the products of the vir genes which are grouped into six distinct loci. the largest is the virb locus spanning 9.5 kb. transposon mutagenesis studies have shown that virb gene products are required for virulence but their functions remain largely unknown. to prov ... | 1990 | 2370849 |
| osmotic regulation of beta(1-2) glucan synthesis in members of the family rhizobiaceae. | high osmolarity in the culture medium of growing agrobacterium tumefaciens strongly inhibited the accumulation of cellular beta(1-2) glucan. however, the enzymatic system required for the synthesis of this polysaccharide from udp-glucose was not repressed by high osmolarity. mutants of a. tumefaciens and rhizobium meliloti affected in beta(1-2) glucan synthesis were unable to grow normally in low-osmolarity media. | 1990 | 2376569 |
| growth of agrobacterium tumefaciens under octopine limitation in chemostats. | agrobacterium tumefaciens b6 and atcc 15955 were grown under octopine or glutamate limitation in chemostats. examination of the maximum specific growth rate (mu max) and substrate affinity (ks) for each strain indicated that strain b6 was highly inefficient in its use of octopine as either a nitrogen or carbon source compared with strain atcc 15955. examination of the yield coefficients showed that in both strains octopine was used more efficiently as a nitrogen source than as a carbon source. t ... | 1990 | 2383013 |
| phosphorylation of the virg protein of agrobacterium tumefaciens by the autophosphorylated vira protein: essential role in biological activity of virg. | agrobacterium tumefaciens virulence genes are induced by plant signals through the vira-virg two-component regulatory system. the vira protein is a membrane-spanning sensor molecule that possesses an autophosphorylating activity, and the virg protein is a sequence-specific dna-binding protein. in this report, we demonstrate that the virg protein is phosphorylated by the vira protein and that the phosphate is directly transferred from the phosphorylated vira molecule (phosphohistidine) to the vir ... | 1990 | 2394678 |
| identification of a virb10 protein aggregate in the inner membrane of agrobacterium tumefaciens. | products of the virb operon are proposed components of a membrane-associated t-dna transport apparatus in agrobacterium tumefaciens. here we identified the virb10 gene product and raised specific antiserum to the protein. while the virb10 reading frame contains two potential atg translation start sites located 32 codons apart, we found that only the downstream atg was required for efficient virb10 synthesis. cellular localization studies and analysis of translational fusions with the escherichia ... | 1990 | 2394684 |
| the vira protein of agrobacterium tumefaciens is autophosphorylated and is essential for vir gene regulation. | the vira and virg gene products are required for the regulation of the vir regulon on the tumor-inducing (ti) plasmid of agrobacterium tumefaciens. vira is a membrane-associated protein which is homologous to the sensor molecules of other two-component regulatory systems. we overproduced truncated vira proteins in escherichia coli by deleting different lengths of the 5'-coding region of the vira gene and placing these genes under lacz control. these proteins were purified from polyacrylamide gel ... | 1990 | 2404940 |
| the regulatory virg protein specifically binds to a cis-acting regulatory sequence involved in transcriptional activation of agrobacterium tumefaciens virulence genes. | virulence genes of agrobacterium tumefaciens are induced in parallel in the presence of plant phenolic compounds such as acetosyringone and the two regulatory vir genes vira and virg. in this study we identified a cis-acting regulatory sequence in the 5'-noncoding region of the vire operon that is essential for this activation. to do this, we constructed a series of deletion mutants by using exonuclease bal 31. western blot (immunoblot) analysis showed that the 70 base pairs upstream of the tran ... | 1990 | 2404941 |
| nucleotide sequence, secondary structure and evolution of the 5s ribosomal rna from five bacterial species. | the nucleotide sequences of the 5s ribosomal rnas of the bacteria agrobacterium tumefaciens, alcaligenes faecalis, pseudomonas cepacia, aquaspirillum serpens and acinetobacter calcoaceticus have been determined. the sequences fit in a generally accepted model for 5s rna secondary structure. however, a closer comparative examination of these and other bacterial 5s rna primary structures reveals the potential of additional base pairing and of multiple equilibria between a set of slightly different ... | 1985 | 2408888 |
| natural relationship between bacteroides and flavobacteria. | comparisons among 16s rrna sequences from various eubacteria reveal a natural relationship between the bacteroides (represented by the bacteroides fragilis sequence) and a phylogenetic unit that comprises the flavobacteria, cytophagae, flexibacteria, and others (represented by the flavobacterium heparinum sequence). although the relationship is not a close one, it is, nevertheless, specific. rrnas from these two organisms are not only closer to one another in overall sequence than they are to ou ... | 1985 | 2413007 |
| urinary tract infection probably caused by agrobacterium radiobacter. | | 1985 | 2419130 |
| analysis of cell division gene ftsz (sulb) from gram-negative and gram-positive bacteria. | the ftsz (sulb) gene of escherichia coli codes for a 40,000-dalton protein that carries out a key step in the cell division pathway. the presence of an ftsz gene protein in other bacterial species was examined by a combination of southern blot and western blot analyses. southern blot analysis of genomic restriction digests revealed that many bacteria, including species from six members of the family enterobacteriaceae and from pseudomonas aeruginosa and agrobacterium tumefaciens, contained seque ... | 1987 | 2432055 |
| genetic analysis of agrocin 84 production and immunity in agrobacterium spp. | mutations affecting agrocin production on the 48-kilobase (kb) plasmid, pagk84, can be complemented in trans with cloned portions of the plasmid. five complementation groups ranging in minimum size from 1.2 to 5.6 kb were identified within a 14-kb segment. plasmid pagk84-encoded immunity to agrocin 84 was located to two separate regions of the plasmid. either region alone was sufficient to protect sensitive strains, and both loci mapped to the agrocin 84 biosynthesis region. one region is locate ... | 1987 | 2442139 |
| genes responsible for the supervirulence phenotype of agrobacterium tumefaciens a281. | agrobacterium tumefaciens a281 induces large, rapidly appearing tumors on a variety of plants and has a wider host range than other strains of a. tumefaciens. by using tn3hoho1 transposon mutagenesis and complementation analysis, a 2.5-kilobase dna fragment which is responsible for the supervirulence phenotype was identified in the virulence (vir) region of the ti plasmid. this fragment contains the virg locus, as well as the 3' end of the virb operon. a clone of this fragment conferred the supe ... | 1987 | 2443480 |
| expression of an agrobacterium ti plasmid gene involved in cytokinin biosynthesis is regulated by virulence loci and induced by plant phenolic compounds. | the nopaline-type ti plasmid t37 of agrobacterium tumefaciens carries two distinct genes that encode enzymes involved in cytokinin biosynthesis. in this report, we show that the level of expression of one of these genes was increased dramatically by culture conditions that increased the expression of ti plasmid virulence genes, including coculture with plant cells or treatment with acetosyringone, a plant phenolic compound. when this nopaline-type ti plasmid gene was introduced into agrobacteriu ... | 1988 | 2448293 |
| agrobacterium tumefaciens vire operon encodes a single-stranded dna-binding protein. | the virulence (vir) genes of agrobacterium tumefaciens ti plasmid are essential for transformation of plant cells. overproduction of a vire-encoded gene product in escherichia coli was achieved by construction of an operon fusion with the e. coli tryptophan (trp) operon. the vire2 gene product in e. coli partitioned into the insoluble membrane fraction. the protein was solubilized by treatment with 4 m urea at 0 degree c. dna-protein binding experiments showed that a strong single-stranded (ss) ... | 1988 | 2452439 |
| selective recovery of foreign gene transcripts as virus-like particles in tmv-infected transgenic tobaccos. | a short origin-of-assembly sequence (oas) located in the 30kda movement protein gene, about 1.0kb from the 3'-end of the common strain of tobacco mosaic virus (tmv) rna, nucleates encapsidation of the 6395-nucleotide-long genome by tmv coat protein in vitro, and presumably also in vivo. single-stranded rnas containing a foreign reporter gene sequence and the tmv oas at their 5' - and 3' -ends, respectively, can be synthesized in vitro from recombinant sp6-transcription plasmids and will assemble ... | 1988 | 2453837 |
| transient transfection of mammalian cells with dna of the plant-pathogenic ti-plasmid and expression of marker and resident sequences. | the large ti-plasmid from agrobacterium tumefaciens strain c58 has been used for transfection experiments with mammalian cells. in dna from tupaia baby fibroblasts ti-plasmid sequences could be identified by filter hybridization as long as four weeks after transfection including two cell passages. the hybridization signals decreased rapidly after addition of the ti-plasmid dna-coprecipitate to the cells. the signals were often not detected any more after the first day, but were visible one week ... | 1989 | 2471056 |
| the maize en-1/spm element transposes in potato. | the maize transposable element en-1 has been introduced into a diploid potato line via transformation with agrobacterium tumefaciens. the element is transcriptionally active in potato. numerous en specific rnas are observed, including a 6 kb transcript characteristic of an active en-1 element in maize. in contrast to maize, where the 6.0 kb transcript is hardly detectable, this transcript is very abundant in the transgenic potato. transposition of en-1 in the potato clone was analysed by souther ... | 1989 | 2475754 |
| overproduction of alfalfa glutamine synthetase in transgenic tobacco plants. | we have obtained transgenic tobacco plants overexpressing the enzyme glutamine synthetase (gs) by fusing an alfalfa gs gene to the cauliflower mosaic virus 35s promotor and integrating it into nicotiana tabacum var. w38 plants by agrobacterium tumefaciens mediated gene transfer. the amount of rna specific to alfalfa gs was about 10 times higher in transgenic tobacco plants than in alfalfa. the alfalfa gs produced by these transgenic plants was identified by western blotting and represented 5% of ... | 1989 | 2475755 |
| extensive changes in dna methylation patterns accompany activation of a silent t-dna ipt gene in agrobacterium tumefaciens-transformed plant cells. | we crossed a male-sterile, agrobacterium-transformed nicotiana tabacum plant that contains a silent, hypermethylated t-dna ipt oncogene with a normal tobacco plant and found that the methylated state of the ipt gene was stably inherited through meiosis in the offspring. however, when tissues of these plants were placed in cell culture, the ipt gene was spontaneously reactivated in a very small fraction of the cells; if 5-azacytidine was added to the culture medium, ipt gene reactivation occurred ... | 1989 | 2479825 |
| phleomycin resistance as a dominant selectable marker for plant cell transformation. | tobacco cells are sensitive to bleomycin and phleomycin. the tn5 and the streptoalloteichus hindustanus (sh) bleomycin resistance ('ble') genes conferring resistance to these antibiotics have each been inserted into two plant expression vectors. they are flanked by the nopaline synthase (nos) or the cauliflower mosaic virus (camv) 35s promoters on one side, and by the nos polyadenylation signal on the other. these four chimaeric genes were introduced into the binary transformation vector pga 492 ... | 1989 | 2485087 |
| expression of a c3 plant rubisco ssu gene in regenerated c4 flaveria plants. | we report the successful transformation, via agrobacterium tumefaciens infection, and regeneration of two species of the genus flaveria: f. brownii and f. palmeri. we document the expression of a c3 plant gene, an abundantly expressed ribulose 1,5-bisphosphate carboxylase/oxygenase small subunit gene isolated from petunia, in these c4 plants. the organ-specific expression of this petunia gene in flaveria brownii is qualitatively identical to its endogenous pattern of expression. | 1989 | 2491665 |
| mutational analysis of the conserved domains of a t-region border repeat of agrobacterium tumefaciens. | left- and right-border repeats, which surround the t-region, contain two conserved regions separated by 5 bp that are not conserved. at the onset of t-dna processing vird-encoded proteins introduce a nick in the largest of these conserved regions (12 bp) at a specific position in the bottom strand between a guanine and thymine nucleotide [2, 33]. in this paper we describe the effect of several site-directed mutations in the right-border repeat on tumorigenicity of agrobacterium in plants. our da ... | 1989 | 2491670 |
| single-stranded dna used as an efficient new vehicle for transformation of plant protoplasts. | in relation to the question which dna form (single- or double-stranded) is transferred by agrobacterium tumefaciens to plant cells, we studied the behaviour of single-stranded dna, as compared to double-stranded dna, when it is introduced into plant protoplasts by electroporation. to this end, we cloned a construct with a plant nptii gene as well as a cat gene in the m13 vectors tg130 and tg131. we found that both complementary single-stranded molecules gave rise to substantial cat activity in p ... | 1989 | 2491686 |
| nucleotide sequence and genetic organization of the bacillus subtilis comg operon. | a series of tn917lac insertions define the comg region of the bacillus subtilis chromosome. comg mutants are deficient in competence and specifically in the binding of exogenous dna. the genes included in the comg region are first expressed during the transition from the exponential to the stationary growth phase. from nucleotide sequence information, it was concluded that the comg locus contains seven open reading frames (orfs), several of which overlap at their termini. high-resolution s1 nucl ... | 1989 | 2507524 |
| chva locus may be involved in export of neutral cyclic beta-1,2-linked d-glucan from agrobacterium tumefaciens. | extracellular and intracellular neutral beta-1,2-linked d-glucan content was determined in a virulent, attachment-deficient mutants of agrobacterium tumefaciens that map in the chva locus. chva mutants contained approximately the same amount of intracellular glucan as cells of the virulent control strain a759, but released into the culture medium only 2% of the glucan released by strain a759. introduction of a cosmid carrying the wild-type chv region restored attachment and virulence and restore ... | 1989 | 2520158 |
| expression of agrobacterium nopaline-specific vird1, vird2, and virc1 proteins and their requirement for t-strand production in e. coli. | induction of ti plasmid virulence (vir) genes during early stages of the genetic transformation of plant cells by agrobacterium tumefaciens results in several molecular events that are involved in generating a transferable t-dna copy. these events include site-specific nicking at the t-dna borders and synthesis of free, unipolar, linear, single-stranded copies of the t-dna (t-strands). here e. coli was used as a heterologous cell to assay the requirements for t-strand synthesis. cells of e. coli ... | 1989 | 2520160 |
| identification, cloning, and sequence analysis of the nitrogen regulation gene ntrc of agrobacterium tumefaciens c58. | we describe the cloning of an ntrc gene of agrobacterium tumefaciens c58 by interspecific complementation of an escherichia coli ntrc mutant. restriction mapping and southern blot analysis of the complementing clone identified a 1.7-kb ecori-pvuii dna fragment whose sequence was determined. analysis of this sequence revealed coding regions corresponding to a complete ntrc gene and the c-terminal region of an ntrb gene. amino acid sequence comparisons of a. tumefaciens ntrc protein with ntrc sequ ... | 1989 | 2520824 |
| cloning and analysis of genes involved in coenzyme b12 biosynthesis in pseudomonas denitrificans. | cobalamin synthesis probably requires 20 to 30 different enzymatic steps. pseudomonas putida and agrobacterium tumefaciens mutants deficient in cobalamin synthesis (cob have been isolated. in p. putida, cob mutants were identified as being unable to use ethanolamine as a source of nitrogen in the absence of added cobalamin (deamination of ethanolamine requires coenzyme b12 as a cofactor). in a. tumefaciens, cob mutants were simply screened for their reduced cobalamin synthesis. a genomic library ... | 1989 | 2536665 |
| sequence determination and characterization of the replicator region in the tumor-inducing plasmid ptib6s3. | the replicator region of the 195-kilobase-pair (kb) tumor-inducing plasmid ptib6s3 was previously identified by isolation of a 6.8-kb miniplasmid (b.p. koekman, p.j.j. hooykaas, and r.a. schilperoort, plasmid 7:119-132, 1982). this miniplasmid was joined to cole1-based vectors and subjected to mutagenesis. the resulting mutant plasmids were examined for their ability to replicate autonomously in agrobacterium tumefaciens. it was found that a 4.2-kb region was sufficient for displaying replicatio ... | 1989 | 2537824 |
| the vird operon of agrobacterium tumefaciens ti plasmid encodes a dna-relaxing enzyme. | the vird locus of agrobacterium tumefaciens ti plasmid encodes functions necessary for endonucleolytic cleavage of transferred dna (t-dna) prior to its transfer to plant cells. for the overproduction of the vird proteins in escherichia coli a tac-vird operon fusion was constructed. a significant increase in the accumulation of vird proteins was observed in a lon protease-deficient e. coli host. the presence of an overlapping open reading frame (orf) upstream of the vird1 coding sequence had a ne ... | 1989 | 2541431 |
| identification of insertion sequence element is427 in ptit37 plasmid dna of an agrobacterium tumefaciens t37 isolate. | the isolation and characterization of an insertion sequence (is) element, is427, from agrobacterium tumefaciens t37 is described. is427 is present in three nonidentical copies on the ptit37 plasmid. the copy that was isolated through transposition on the entrapment vector pucd800 contains at its ends a 16-bp imperfect inverted repeat and generates a 2-bp duplication of the target dna. is427 does not show homology with previously characterized is elements of a. tumefaciens, based on hybridization ... | 1989 | 2544912 |
| nucleotide sequence, evolutionary origin and biological role of a rearranged cytokinin gene isolated from a wide host range biotype iii agrobacterium strain. | a dna fragment with homology to the cytokinin (ipt) gene from biotype i agrobacterium tumefaciens strain ach5 was cloned from the ti plasmid of the wide host range biotype iii agrobacterium strain tm-4 and sequenced. the fragment contains an intact ipt coding sequence. however, the 3' non-coding region of this ipt gene is rearranged due to a 0.9 kb deletion fusing it to the 3' coding region of the neighbouring gene 6a, most of which was found to be deleted. the tm-4 ipt gene is strongly related ... | 1989 | 2546041 |
| an ice nucleation reporter gene system: identification of inducible pathogenicity genes in pseudomonas syringae pv. phaseolicola. | we have constructed derivatives of the transposon tn3 that allow an ice nucleation gene (inaz) to be used as 'reporter' of the transcriptional activity of genes into which it is inserted. in these derivatives (tn3-ice and tn3-spice), the laczya sequences of transposon tn3-hoho1 were replaced with inaz lacking its native promoter. the ice nucleation activity of virb::inaz fusions in the correct transcriptional orientation was inducible by acetosyringone, a plant metabolite which activates the vir ... | 1989 | 2548841 |
| sequence and distribution of is866, a novel t region-associated insertion sequence from agrobacterium tumefaciens. | we have identified a new insertion sequence, is866, located in the auxin synthesis gene ta iaah of tm4, a wide host range biotype iii octopine/cucumopine type agrobacterium tumefaciens strain with two t regions on its tumor-inducing (ti) plasmid, ta, and tb. is866 is 2716 bp long, has inverted repeats of 27 bp with three mismatches, and generates 8-bp direct repeats upon integration. in addition to is866, ptitm4 carries two copies of a related element, is867, associated with ta and tb, respectiv ... | 1989 | 2550985 |
| characterization of conjugal transfer functions of agrobacterium tumefaciens ti plasmid ptic58. | physical characterization of 13 transposon tn5 insertions within the agrocinopine-independent, transfer-constitutive ti plasmid ptic58trac identified three separate loci essential for conjugation of this nopaline/agrocinopine a + b-type ti plasmid. complementation analysis with relevant subcloned dnas indicated that the three physically separated blocks of conjugal genes constitute distinct complementation groups. two independent tn5 insertions within the wild-type, agrocinopine-dependent, repre ... | 1989 | 2551885 |
| cyclic diguanylic acid and cellulose synthesis in agrobacterium tumefaciens. | the occurrence of the novel regulatory nucleotide bis(3',5')-cyclic diguanylic acid (c-di-gmp) and its relation to cellulose biogenesis in the plant pathogen agrobacterium tumefaciens was studied. c-di-gmp was detected in acid extracts of 32p-labeled cells grown in various media, and an enzyme responsible for its formation from gtp was found to be present in cell-free preparations. cellulose synthesis in vivo was quantitatively assessed with [14c]glucose as a tracer. the organism produced cellul ... | 1989 | 2556370 |
| covalently bound vird2 protein of agrobacterium tumefaciens protects the t-dna from exonucleolytic degradation. | we show that upon induction of agrobacterium tumefaciens, free linear double-stranded t-dna molecules as well as the previously described t-strands are generated from the ti plasmid. a majority of these molecules are bound to a protein. we show that this protein is the product of the virulence gene vird2. this protein was found to be attached to the 5' terminus of processed t-dna at the right border and to the rest of the ti plasmid at the left border. the protein remnant after pronase digestion ... | 1989 | 2556703 |
| a comparative study of tam3 and ac transposition in transgenic tobacco and petunia plants. | transposition of the anthirrinum majus tam3 element and the zea mays ac element has been monitored in petunia and tobacco plants. plant vectors were constructed with the transposable elements cloned into the leader sequence of a marker gene. agrobacterium tumefaciens-mediated leaf disc transformation was used to introduce the transposable element constructs into plant cells. in transgenic plants, excision of the transposable element restores gene expression and results in a clearly distinguishab ... | 1989 | 2562396 |
| agrobacterium radiobacter and cdc group ve-2 bacteremia. | agrobacterium radiobacter and cdc group ve-2 are rare human pathogens. the simultaneous infection with both of these bacteria in an immunocompromised host is reported. review of the ucla microbiology laboratory records revealed one additional case of a. radiobacter bacteremia and two additional cases of cdc group ve-2 bacteremia over a 3-year period. the clinical experience with these organisms is reviewed. both organisms are opportunistic pathogens with a predilection for patients with foreign ... | 1989 | 2591169 |
| the agrobacterium tumefaciens virc1 gene product binds to overdrive, a t-dna transfer enhancer. | in agrobacterium tumefaciens, a cis-active 24-base-pair sequence adjacent to the right border of the t-dna, called overdrive, stimulates tumor formation by increasing the level of t-dna processing. recent results from our laboratory have suggested that the virc operon which enhances t-dna processing probably does so because the virc1 protein interacts with overdrive (n. toro, a. datta, m. yanofsky, and e. w. nester, proc. natl. acad. sci. usa 85:8558-8562, 1988). we report here the purification ... | 1989 | 2592351 |
| developmental and environmental regulation of a phenylalanine ammonia-lyase-beta-glucuronidase gene fusion in transgenic tobacco plants. | a 1.1-kilobase promoter fragment of the bean (phaseolus vulgaris l.) phenylalanine ammonia-lyase (ec 4.3.1.5) gene pal2 was translationally fused to the beta-glucuronidase reporter gene and transferred to tobacco by agrobacterium tumefaciens-mediated leaf disk transformation. the distribution of beta-glucuronidase activity in these transgenic plants is very similar to that of endogenous pal2 transcripts in bean, with very high levels in petals; marked accumulation in anthers, stigmas, roots, and ... | 1989 | 2594769 |
| binding-protein-dependent sugar transport by agrobacterium radiobacter and a. tumefaciens grown in continuous culture. | binding-protein-dependent sugar transport has been investigated in agrobacterium radiobacter and a. tumefaciens. a. radiobacter contained two high-affinity glucose-binding proteins (gbp1 and gbp2) that additionally bound d-galactose (kd 0.26 microm) and d-xylose (kd 0.04 microm) respectively and were involved in the transport of these sugars. partial sequencing of gbp1 and gbp2 showed that gbp2 exhibited significant homology with both the arabinose-binding protein (abp) and the galactose-binding ... | 1989 | 2614377 |
| a translational enhancer derived from tobacco mosaic virus is functionally equivalent to a shine-dalgarno sequence. | when present at the 5' end of mrnas, the untranslated leader sequence (omega) of tobacco mosaic virus rna significantly enhances translation in eukaryotes and prokaryotes. we have tested a deletion derivative of the omega sequence, omega delta 3, for its enhancing ability on gene constructs in which the ribosomal binding site was either present or deleted, in several gram-negative bacterial species including escherichia coli, agrobacterium tumefaciens, xanthomonas campestris pv. vitians, erwinia ... | 1989 | 2643095 |
| ornithine cyclodeaminase from octopine ti plasmid ach5: identification, dna sequence, enzyme properties, and comparison with gene and enzyme from nopaline ti plasmid c58. | octopine and nopaline are two arginine-derived opines synthesized in plant cells transformed with octopine or nopaline plasmids. utilization in agrobacterium tumefaciens is mediated by ti plasmid regions called occ or noc (octopine or nopaline catabolism), and recent experiments showed that noc in ptic58 codes for a pathway from nopaline to l-proline. the last enzyme is ornithine cyclodeaminase (ocd), an unusual protein converting l-ornithine directly into l-proline. we investigated whether octo ... | 1989 | 2644238 |
| molecular cloning of a gene for indole-3-acetamide hydrolase from bradyrhizobium japonicum. | a plafr1 cosmid genomic library of wild-type bradyrhizobium japonicum j1063 was constructed. a cosmid clone designated pbjj4, containing a 26-kilobase (kb) dna insert, was identified as being able to confer the ability to convert alpha-naphthaleneacetamide acid on b. japonicum j1b7 rifr, which cannot perform this conversion. the gene coding for the enzyme that converts alpha-naphthaleneacetamide to alpha-naphthaleneacetic acid was localized in the 3.5-kb region of pbjj4 by recloning in plasmid p ... | 1989 | 2646294 |
| integration of multiple copies of a foreign sequence into the ti plasmid of agrobacterium tumefaciens. | a method for constructing ti plasmids bearing multiple copies of a sequence integrated in tandem is described. a small plasmid that confers tetracycline resistance (tcr), contains homology to a ti plasmid, and is unable to replicate in agrobacterium tumefaciens, was mobilized from escherichia coli to a. tumefaciens. ti plasmids of exconjugants selected for resistance to 12-14 micrograms tc/ml all contained multiple tandem repeats of the integrative plasmid. tc-sensitive variants with fewer integ ... | 1989 | 2653967 |
| the nucleotide sequence of a soybean mosaic virus coat protein-coding region and its expression in escherichia coli, agrobacterium tumefaciens and tobacco callus. | a dna complementary to the 3'-terminal 1168 nucleotides of the genome of the n strain of soybean mosaic virus (smv) has been cloned and sequenced. cdna sequence and coat protein analyses indicate that the smv coat protein-coding region is at the 3' end of the genome, and that the coat protein is processed from a larger protein. the coat protein-coding sequence is predicted to be 795 nucleotides in length, encoding a protein of 265 amino acids with a calculated mr of 29,857. the 3' untranslated r ... | 1989 | 2661723 |
| plant viruses: a tool-box for genetic engineering and crop protection. | traditionally, plant viruses are viewed as harmful, undesirable pathogens. however, their genomes can provide several useful 'designer functions' or 'sequence modules' with which to tailor future gene vectors for plant or general biotechnology. the majority (77%) of known plant viruses have single-stranded rna of the messenger (protein coding) sense as their genetic material. over the past 4 years, improved in vitro transcription systems and the construction of partial or full-length dna copies ... | 1989 | 2662963 |