| identification of closely related agrobacterium vitis isolates by chromosomal dna probes. | crown gall formation on grapevine by agrobacterium vitis is an important plant disease in many regions of the world. on grapevine, octopine/cucumopine (o/c) strains are widely distributed. here we describe two chromosomal sequences of o/c strains of 15 and 20 kb, which reveal a high degree of polymorphism in different o/c isolates. part of the polymorphism is due to the presence or absence of a 2.2-kb-long repeated sequence, a homolog of which is also found on the octopine ti plasmid of ach5, im ... | 1992 | 1341986 |
| physical map of the vitopine ti plasmid ptis4. | within the agrobacterium vitis group the vitopine strains represent a special subclass. vitopine bacteria carry ti plasmids with little or no homology with the well-characterized t-dnas of agrobacterium tumefaciens or agrobacterium rhizogenes. the 262-kb ti plasmid of the vitopine strain s4 was cloned and mapped. homology studies with the octopine ti plasmid ptiach5, the nopaline ti plasmid ptic58, and the agropine/mannopine ri plasmid prihri identified several regions of homology. the origin of ... | 1992 | 1409971 |
| organization and functional analysis of three t-dnas from the vitopine ti plasmid ptis4. | the vitopine ti plasmid ptis4 of agrobacterium vitis has an unusual t-dna organization. the ptis4 oncogenes, localized by screening selected ptis4 clones for growth-inducing activity, are localized on three t-dnas, whereas in all other characterized ti plasmids one or two t-dnas are found. the nucleotide sequences and predicted amino acid sequences of the ptis4 oncogenes set them apart from the corresponding genes from other ti or ri plasmids. the oncogenes induce the same type of reaction on va ... | 1992 | 1465104 |
| sequence and mutational analysis of a tartrate utilization operon from agrobacterium vitis. | the grapevine is the natural host of the tumorigenic bacterium agrobacterium vitis. most of the a. vitis isolates can use tartrate, an unusually abundant compound in grapevine. the nopaline strain, ab4, contains a 170-kb conjugative plasmid (ptrab4) encoding tartrate utilization. a 5.65-kb ptrab4 region which enables non-tartrate-utilizing agrobacterium tumefaciens to grow on tartrate was sequenced and mutagenized with the transcriptional fusion transposon tn5-uida1. this dna fragment contains f ... | 1995 | 7592429 |
| fragmentations of the large-subunit rrna in the family rhizobiaceae. | a 130-nucleotide-long rrna species corresponding to the 5' end of the 23s rrna gene was found in 96 strains belonging to different rhizobium, bradyrhizobium, and agrobacterium species. additional fragmentation in the central region of the large-subunit rrna occurred in all agrobacteria, except agrobacterium vitis, and in most rhizobium leguminosarum and rhizobium etli strains but did not occur in any of the other rhizobia and bradyrhizobia studied. | 1995 | 7592497 |
| a full factorial analysis of nine factors influencing in vitro antagonistic screens for potential biocontrol agents. | the effect of nine factors on the outcome of classic in vitro screens testing the antagonistic action of endophytic bacterial isolates from grape vines against virulent agrobacterium vitis has been examined. these factors were (i) the strain of a. vitis, (ii) the strain of endophyte, (iii) the growth medium of the pathogen, (iv) the growth medium of the endophyte, (v) the temperature of growth of the pathogen, (vi) the temperature of growth of the endophyte, (vii) the ph of growth of the pathoge ... | 1995 | 7736357 |
| agrobacterium vitis nopaline ti plasmid ptiab4: relationship to other ti plasmids and t-dna structure. | the ti plasmid of the agrobacterium vitis nopaline-type strain ab4 was subcloned and mapped. several regions of the 157 kb ti plasmid are similar or identical to parts of the a. vitis octopine/cucumopine (o/c)-type ti plasmids, and other regions are homologous to the nopaline-type ti plasmid ptic58. the t-dna of ptiab4 is a chimaeric structure of recent origin: the left part is 99.2% homologous to the left part of the ta-dna of the o/c-type ti plasmids, while the right part is 97.1% homologous t ... | 1994 | 7808399 |
| a new agrobacterium strain isolated from aerial tumors on ficus benjamina l. | crown gall tumors, collected from branches of 1-year-old weeping fig (ficus benjamina l.) trees, yielded both tumorigenic and nonpathogenic agrobacteria. on the basis of classical diagnostic tests, the nonpathogenic strains were identified as agrobacterium tumefaciens, whereas the tumorigenic strains could not be assigned to any of the known terrestrial agrobacterium spp. the tumorigenic strains also differed from other members of the genus by producing more acid from mannitol. according to clus ... | 1995 | 7887626 |
| natural instability of agrobacterium vitis ti plasmid due to unusual duplication of a 2.3-kb dna fragment. | the octopine/cucumopine (o/c) ti plasmids of agrobacterium vitis carry two t regions, ta and tb. the ta region resembles the octopine tl region. the tb region contains the auxin synthesis genes tb-iaam and tb-iaah and the cucumopine synthesis gene cus. within the group of o/c isolates, strains 2608 and 2641 are closely related. however, 2641 lacks the tb region. the restriction maps of pti2608 and pti2641 were established and showed that the tb deletion resulted from intramolecular recombination ... | 1994 | 8012038 |
| rapid divergence of agrobacterium vitis octopine-cucumopine ti plasmids from a recent common ancestor. | the octopine/cucumopine (o/c) ti plasmids of the grapevine-associated agrobacterium vitis strains constitute a family of related dna molecules. restriction maps were established of two limited-host-range o/c ti plasmids, ptiag57 and ptiab3, and of the wide-host-range o/c ti plasmid ptihm1. together with the previously obtained map of the wide-host-range o/c ti plasmid ptitm4, about 1000 kb were mapped with a resolution of 0.2 kb, allowing a detailed comparison of the various structures. one regi ... | 1993 | 8101965 |
| proposal for rejection of agrobacterium tumefaciens and revised descriptions for the genus agrobacterium and for agrobacterium radiobacter and agrobacterium rhizogenes. | the 16s rrna sequences of seven representative agrobacterium strains, eight representative rhizobium strains, and the type strains of azorhizobium caulinodans and bradyrhizobium japonicum were determined. these strains included the type strains of agrobacterium tumefaciens, agrobacterium rhizogenes, agrobacterium radiobacter, agrobacterium vitis, agrobacterium rubi, rhizobium fredii, rhizobium galegae, rhizobium huakuii, rhizobium leguminosarum, rhizobium loti, rhizobium meliloti, and rhizobium ... | 1993 | 8240952 |
| is870 requires a 5'-ctag-3' target sequence to generate the stop codon for its large orf1. | the tb regions of the agrobacterium vitis octopine/cucumopine ti plasmids constitute a family of related structures. all contain a bacterial insertion element downstream of the tb-iaam gene, is870.1. whereas 43 isolates with octopine/cucumopine ti plasmids carry only one is870 copy, strain ag57 carries a second copy (is870.2) 3.9 kb to the right of is870.1 and part of the same tb region. two other octopine/cucumopine strains carry an is870 copy on their chromosome (is870.3). a study of the unmod ... | 1993 | 8387998 |
| the ti plasmid from the wide host range agrobacterium vitis strain tm4: map and homology with other ti plasmids. | the octopine/cucumopine (o/c) strains of agrobacterium vitis are divided into limited (lhr) and wide host range (whr) strains. we present here the first map of a ti plasmid from a whr o/c strain, tm4. ptitm4 (252 kb) has homology with the octopine ti plasmid ptiach5, the nopaline plasmid ptic58, and the ri plasmid prihri. approximately 155 kb of ptitm4 is homologous with the lhr o/c ti plasmids ptiab3 and ptiag57, the remaining part is ptitm4-specific. our data suggest that the evolution of the ... | 1993 | 8469721 |
| variability of the 5'-end of the large subunit rdna and presence of a new short class of rrna in rhizobiaceae. | a highly variable region of dna was found between positions 115 and 388 (escherichia coli numeration) of the large subunit (ls) rrna genes of 55 rhizobial and agrobacterial strains. in each case this heterogeneity was accompanied by the presence of a new rrna species approximately 130 bp long. this novel rrna species corresponded to the 5'-end of the ls rrna genes. an additional rrna processing site was located in the central region of the remaining ls rrna of many of the rhizobium leguminosarum ... | 1995 | 8554768 |
| sequence and characterisation of a ribosomal rna operon from agrobacterium vitis. | one of the four ribosomal rna operons (rrna) from the agrobacterium vitis vitopine strain s4 was sequenced, rrna is most closely related to the rrn operons of bradyrhizobium japonicum and rhodobacter sphaeroides and carries an fmet-trna gene downstream of its 5s gene, as in the case of r. sphaeroides. the 16s rrna sequence of s4 differs from the a. vitis k309 type strain sequence by only one nucleotide, in spite of the fact that s4 and k309 have very different ti plasmids. the predicted secondar ... | 1996 | 8628253 |
| major differences between the rrna operons of two strains of agrobacterium vitis. | the sequence of the rrna operon and its flanking regions was determined for the agrobacterium vitis type strain ncppb3554. compared to the earlier obtained rrna sequence of a. vitis strain s4, several important differences were noted: the sequences diverged at the 5'-flanking region, within the 16s-23s intergenic region, and within the 23s rrna sequence. the b8 stem-loop structure at the 5'-end of the 23s rrna of strain ncppb3554 was 142 nt shorter than that of strain s4. these findings have imp ... | 1996 | 8661947 |
| characterization and distribution of tartrate utilization genes in the grapevine pathogen agrobacterium vitis. | agrobacterium vitis is a common pathogen of grapevine. most strains utilize tartrate, an abundant compound in grapevine. strain ab3 carries two tartrate utilization (or tar) regions: tar-i (on the large ptrab3 plasmid) and tar-ii (on the ab3 ti plasmid). tar-i and tar-ii were structurally and functionally analyzed and are similar to the tar-iii region from the tartrate utilization plasmid ptrab4 of the nopaline-type a. vitis strain ab4 (crouzet and otten, j. bacteriol. 1995, 177:6518-6526). the ... | 1996 | 8672817 |
| characterization of the agrobacterium vitis peha gene and comparison of the encoded polygalacturonase with the homologous enzymes from erwinia carotovora and ralstonia solanacearum. | dna sequencing of the agrobacterium vitis peha gene revealed a predicted protein with an m(r) of 58,000 and significant similarity to the polygalacturonases of two other plant pathogens, erwinia carotovora and ralstonia (= pseudomonas or burkholderia) solanacearum. sequencing of the n terminus of the peha protein demonstrated cleavage of a 34-amino-acid signal peptide from pre-peha. mature peha accumulated primarily in the periplasm of a. vitis and peha+ escherichia coli cells during exponential ... | 1997 | 8979363 |
| cloning and expression in escherichia coli of sucrose phosphorylase gene from leuconostoc mesenteroides no. 165. | the sucrose phosphorylase gene of an isolate, leuconostoc mesenteroides no. 165, was amplified by pcr, cloned on puc118, and expressed in e. coli. the nucleotide sequence of the gene showed 96.3% similarity to that of l. mesenteroides atcc12291 and 67% to that of streptococcus mutans, but low similarity to the agrobacterium vitis gene. the cloned gene, which fusing with laczalpha, was expressed inducibly with iptg in e. coli to produce an active enzyme in large quantities that accounted for abou ... | 1996 | 9063982 |
| identification and mutation of a gene required for glycerate kinase activity from a facultative methylotroph, methylobacterium extorquens am1. | a gene (gcka) responsible for the activity of glycerate kinase has been identified within a chromosomal fragment of the serine cycle methylotroph methylobacterium extorquens am1. a mutation in gcka leads to a specific c1-negative phenotype. the polypeptide sequence derived from gcka showed high similarity to a product of ttud essential for tartrate metabolism in agrobacterium vitis. our data suggest that gcka and ttud might be structural genes for glycerate kinase and that the serine cycle and t ... | 1997 | 9244287 |
| incompatibility properties of tartrate utilization plasmids derived from agrobacterium vitis strains. | the incompatibility properties of two tumor-inducing (ti) and seven tartrate (tr) plasmids, derived from various agrobacterium vitis strains, were characterized using incrh1, incrh2, incrh3, and incrh4 clones which were established for the identification and classification of agrobacterium plasmids. the tested a. vitis plasmids could be allocated into four groups on the basis of their incompatibility with incrh1, incrh2, and incrh4 clones. the two octopine tumor-inducing plasmids, ptiat6 and pti ... | 1998 | 9473444 |
| unconventional genomic organization in the alpha subgroup of the proteobacteria. | pulsed-field gel electrophoresis was used to analyze the genomic organization of 16 bacteria belonging or related to the family rhizobiaceae of the alpha subgroup of the class proteobacteria. the number and sizes of replicons were determined by separating nondigested dna. hybridization of an rrn gene probe was used to distinguish between chromosomes and plasmids. members of the genus agrobacterium all possess two chromosomes, and each biovar has a specific genome size. as previously demonstrated ... | 1998 | 9573163 |
| a t-dna from the agrobacterium tumefaciens limited-host-range strain ab2/73 contains a single oncogene. | agrobacterium tumefaciens strain ab2/73 isolated from lippia canescens has been described as a limited-host-range strain. its tumor-inducing (ti) plasmid has been found to lack dna homology to known t-dnas (l. unger, s. f. ziegler, g. a. huffman, v. c. knauf, r. peet, l. w. moore, m. p. gordon, and e. w. nester. j. bacteriol. 164:723-730, 1985). we have isolated a t-dna from ab2/73 by using a heterologous border sequence as a probe. the ab2/73 t-dna sequence (3,504 bp) is flanked by canonical bo ... | 1998 | 9574502 |
| the presence and characterization of a virf gene on agrobacterium vitis ti plasmids. | octopine and nopaline strains of agrobacterium tumefaciens differ in their ability to induce tumors on nicotiana glauca. the presence of a virf locus on the octopine ti plasmid makes n. glauca a host plant for these strains, indicating that the virf protein is a host-range determinant. here we show the presence of a virf locus not only on the agrobacterium vitis octopine/cucumopine plasmids ptiag57 and ptitm4, but also on the nopaline ti plasmids ptiat1, ptiat66a, and ptiat66b. on the octopine t ... | 1998 | 9574510 |
| genetic analysis of dioxin dioxygenase of sphingomonas sp. strain rw1: catabolic genes dispersed on the genome. | the dioxin dioxygenase of sphingomonas sp. strain rw1 activates dibenzo-p-dioxin and dibenzofuran for further metabolism by introducing two atoms of oxygen at a pair of vicinal carbon atoms, one of which is involved in one of the bridges between the two aromatic rings, i.e., an angular dioxygenation. the dxna1 and dxna2 cistrons encoding this dioxygenase have been cloned and shown to be located just upstream of a hydrolase gene which specifies an enzyme involved in the subsequent step of the dib ... | 1998 | 9683494 |
| phylogeny of rhizobium galegae with respect to other rhizobia and agrobacteria. | pcr-rflp with nine restriction enzymes was applied to the 16s and 23s rrna genes of 42 rhizobial and agrobacterial strains to determine the phylogenetic position of rhizobium galegae and increase the understanding of the evolution of ribosomal operons. the strains were selected based on previous phylogenetic studies. pcr primers were designed so that they amplified a 2.3 kb fragment of the 23s rrna gene (excluding the b8 loop). universal primers rd1 and fd1 were used to amplify the full-length 1 ... | 1998 | 9731273 |
| rhizobium huautlense sp. nov., a symbiont of sesbania herbacea that has a close phylogenetic relationship with rhizobium galegae. | the nitrogen-fixing rhizobial symbionts of sesbania herbacea growing in the nature reserve at the sierra de huautla, mexico, were isolated and characterized. all 104 isolates together with the type strain for rhizobium galegae, hambi 540t, had similar 16s rrna genes as revealed by pcr-rflp analysis. similarity in the sequences of the 16s rrna genes placed the isolates on a phylogenetic branch shared with r. galegae. among 66 randomly selected isolates, three closely related electrophoretic alloe ... | 1998 | 9734023 |
| identification of brucella by ribosomal-spacer-region pcr and differentiation of brucella canis from other brucella spp. pathogenic for humans by carbohydrate profiles. | molecular and chemical characteristics often provide complementary information in the differentiation of closely related organisms. the genus brucella consists of a highly conserved group of organisms. identification of the four species pathogenic in humans (brucella melitensis, brucella abortus, brucella suis, and brucella canis) is problematic for many clinical laboratories that depend primarily on serology and phenotypic characteristics to differentiate species. pcr amplification of the 16s-2 ... | 1998 | 9774568 |
| allorhizobium undicola gen. nov., sp. nov., nitrogen-fixing bacteria that efficiently nodulate neptunia natans in senegal. | a group of nodule isolates from neptunia natans, an indigenous stemnodulated tropical legume found in waterlogged areas of senegal, was studied. polyphasic taxonomy was performed, including sds-page of total proteins, auxanography using api galleries, host-plant specificity, pcr-rflp of the internal transcribed spacer region between the 16s and the 23s rrna coding genes, 16s rrna gene sequencing and dna-dna hybridization. it was demonstrated that this group is phenotypically and phylogenetically ... | 1998 | 9828428 |
| characterization of is1547, a new member of the is900 family in the mycobacterium tuberculosis complex, and its association with is6110. | unlike classically defined insertion sequence (is) elements, which are delimited by their inverted terminal repeats, some is elements do not have inverted terminal repeats. among this group of atypical is elements, is116, is900, is901, and is1110 have been proposed as members of the is900 family of elements, not only because they do not have inverted terminal repeats but also because they share other features such as homologous transposases and particular insertion sites. in this study, we repor ... | 1999 | 9922269 |
| liz1p, a novel fission yeast membrane protein, is required for normal cell division when ribonucleotide reductase is inhibited. | ribonucleotide reductase activity is required for generating deoxyribonucleotides for dna replication. schizosaccharomyces pombe cells lacking ribonucleotide reductase activity arrest during s phase of the cell cycle. in a screen for hydroxyurea-sensitive mutants in s. pombe, we have identified a gene, liz1(+), which when mutated reveals an additional, previously undescribed role for ribonucleotide reductase activity during mitosis. inactivation of ribonucleotide reductase, by either hydroxyurea ... | 1999 | 9950674 |
| structure and function of a conserved dna region coding for tartrate utilization in agrobacterium vitis. | three tartrate utilization regions from agrobacterium vitis strains involved in host specificity have been compared, to clearly define the borders of these regions and eventually identify specific sequences that could provide a mechanism of duplication of this region. a 10.8-kb conserved dna fragment called the tar element, found in different genetic contexts, was defined. a comparison of the two tartrate dehydrogenase genes (ttuc and ttuc') in each of the three tar elements suggests that these ... | 1999 | 10339827 |
| an additional regulatory gene for actinorhodin production in streptomyces lividans involves a lysr-type transcriptional regulator. | the sequence of a 4.8-kbp dna fragment adjacent to the right-hand end of the actinorhodin biosynthetic (act) cluster downstream of actvb-orf6 from streptomyces coelicolor a3(2) reveals six complete open reading frames, named orf7 to orf12. the deduced amino acid sequences from orf7, orf10, and orf11 show significant similarities with the following products in the databases: a putative protein from the s. coelicolor scp3 plasmid, lysr-type transcriptional regulators, and proteins belonging to the ... | 1999 | 10400594 |
| characterization of the phthalate permease ophd from burkholderia cepacia atcc 17616. | the ophd gene, encoding a permease for phthalate transport, was cloned from burkholderia cepacia atcc 17616. expression of the gene in escherichia coli results in the ability to transport phthalate rapidly into the cell. uptake inhibition experiments show that 4-hydroxyphthalate, 4-chlorophthalate, 4-methylphthalate, and cinchomeronate compete for the phthalate permease. an ophd knockout mutant of 17616 grows slightly more slowly on phthalate but is still able to take up phthalate at rates equiv ... | 1999 | 10498738 |
| diversity of the limited-host range iaah gene of agrobacterium vitis strain ag162. | the indole-3-acetamide hydrolase gene (iaah) of the limited-host range strain ag162, a biotype iii strain of agrobacterium tumefaciens has been the subject of several studies and reviews, but its primary structure has not been previously reported. in the course of our own work we found that this gene hybridizes only weakly to a nucleic acid probe corresponding to the iaah gene from a biotype i strain of a. tumefaciens. analysis of the primary structure of the ag162 iaah gene revealed that it is ... | 1998 | 10520742 |
| a new chemolithoautotrophic arsenite-oxidizing bacterium isolated from a gold mine: phylogenetic, physiological, and preliminary biochemical studies. | a previously unknown chemolithoautotrophic arsenite-oxidizing bacterium has been isolated from a gold mine in the northern territory of australia. the organism, designated nt-26, was found to be a gram-negative motile rod with two subterminal flagella. in a minimal medium containing only arsenite as the electron donor (5 mm), oxygen as the electron acceptor, and carbon dioxide-bicarbonate as the carbon source, the doubling time for chemolithoautotrophic growth was 7.6 h. arsenite oxidation was f ... | 2000 | 10618208 |
| identification of cold shock gene loci in sinorhizobium meliloti by using a luxab reporter transposon. | using a luxab reporter transposon, seven mutants of sinorhizobium meliloti were identified as containing insertions in four cold shock loci. luxab activity was strongly induced (25- to 160-fold) after a temperature shift from 30 to 15 degrees c. the transposon and flanking host dna from each mutant was cloned, and the nucleic acid sequence of the insertion site was determined. unexpectedly, five of the seven luxab mutants contained transposon insertions in the 16s and 23s rrna genes of two of th ... | 2000 | 10618254 |
| pyruvate kinase of the hyperthermophilic crenarchaeote thermoproteus tenax: physiological role and phylogenetic aspects. | pyruvate kinase (pk; ec 2.7.1.40) of thermoproteus tenax was purified to homogeneity, and its coding gene was cloned and expressed in escherichia coli. it represents a homomeric tetramer with a molecular mass of 49 kda per subunit. pk exhibits positive binding cooperativity with respect to phosphoenolpyruvate and metal ions such as mg(2+) and mn(2+). heterotropic effects, as commonly found for pks from bacterial and eucaryal sources, could not be detected. the enzyme does not depend on k(+) ions ... | 2000 | 10715009 |
| molecular analysis of a tryptophan-2-monooxygenase gene (iaam) of agrobacterium vitis. | tryptophan-2-monooxygenase genes occur in a number of bacteria and encode the conversion of tryptophan to the plant hormone precursor indole-3-acetamide. the role of these genes in the plant-bacteria interaction is often unclear. however, their function as a virulence determinant is established for pseudomonas savastanoi and agrobacterium tumefaciens. some members of the agrobacteria, such as agrobacterium vitis have a limited host range. we have characterized the tryptophan-2-monooxygenase (iaa ... | 1999 | 10727091 |
| characterization of plasmid-borne and chromosome-encoded traits of agrobacterium biovar 1, 2, and 3 strains from france. | we collected 111 agrobacterium isolates from galls of various origins (most of them from france) and analyzed both their plasmid-borne and chromosome-encoded traits. phenotypic analysis of these strains allowed their classification in three phena which exactly matched the delineation of biovars 1, 2, and 3. a fourth phenon was identified which comprises three atypical strains. the phenotypic analysis has also allowed us to identify 12 additional characteristics which could be used to identify th ... | 2000 | 10788345 |
| development of a highly sensitive nested-pcr procedure using a single closed tube for detection of erwinia amylovora in asymptomatic plant material. | a novel method, which involves a nested pcr in a single closed tube, was developed for the sensitive detection of erwinia amylovora in plant material. the external and internal primer pairs used had different annealing temperatures and directed the amplification of a specific dna fragment from plasmid pea29. the procedure involved two consecutive pcrs, the first of which was performed at a higher annealing temperature that allowed amplification only by the external primer pair. using pure cultur ... | 2000 | 10788384 |
| rnase iii processing of intervening sequences found in helix 9 of 23s rrna in the alpha subclass of proteobacteria. | we provide experimental evidence for rnase iii-dependent processing in helix 9 of the 23s rrna as a general feature of many species in the alpha subclass of proteobacteria (alpha-proteobacteria). we investigated 12 rhodobacter, rhizobium, sinorhizobium, rhodopseudomonas, and bartonella strains. the processed region is characterized by the presence of intervening sequences (ivss). the 23s rdna sequences between positions 109 and 205 (escherichia coli numbering) were determined, and potential seco ... | 2000 | 10940010 |
| novel tellurite-amended media and specific chromosomal and ti plasmid probes for direct analysis of soil populations of agrobacterium biovars 1 and 2. | ecology and biodiversity studies of agrobacterium spp. require tools such as selective media and dna probes. tellurite was tested as a selective agent and a supplement of previously described media for agrobacteria. the known biodiversity within the genus was taken into account when the selectivity of k(2)teo(3) was analyzed and its potential for isolating agrobacterium spp. directly from soil was evaluated. a k(2)teo(3) concentration of 60 ppm was found to favor the growth of agrobacteria and r ... | 2001 | 11133429 |
| a revision of rhizobium frank 1889, with an emended description of the genus, and the inclusion of all species of agrobacterium conn 1942 and allorhizobium undicola de lajudie et al. 1998 as new combinations: rhizobium radiobacter, r. rhizogenes, r. rubi, r. undicola and r. vitis. | rhizobium, agrobacterium and allorhizobium are genera within the bacterial family rhizobiaceae, together with sinorhizobium. the species of agrobacterium, agrobacterium tumefaciens (syn. agrobacterium radiobacter), agrobacterium rhizogenes, agrobacterium rubi and agrobacterium vitis, together with allorhizobium undicola, form a monophyletic group with all rhizobium species, based on comparative 16s rdna analyses. agrobacterium is an artificial genus comprising plant-pathogenic species. the monop ... | 2001 | 11211278 |
| elevated temperature differentially affects virulence, virb protein accumulation, and t-pilus formation in different agrobacterium tumefaciens and agrobacterium vitis strains. | that gene transfer to plant cells is a temperature-sensitive process has been known for more than 50 years. previous work indicated that this sensitivity results from the inability to assemble a functional t pilus required for t-dna and protein transfer to recipient cells. the studies reported here extend these observations and more clearly define the molecular basis of this assembly and transfer defect. t-pilus assembly and virulence protein accumulation were monitored in agrobacterium tumefaci ... | 2001 | 11698374 |
| crown gall of grape: biology and disease management. | not until 1973 was it reported that strains of agrobacterium that cause crown gall disease of grape form a specific group (later characterized as agrobacterium vitis). tumorigenic and nontumorigenic a. vitis have since been isolated from infected and symptomless grapes worldwide. research on the genetic makeup of a. vitis has led to an improved understanding of pathogen biology and bacterial evolution. in addition, the identification of significant gene sequences has facilitated the development ... | 1999 | 11701817 |
| two opines control conjugal transfer of an agrobacterium plasmid by regulating expression of separate copies of the quorum-sensing activator gene trar. | conjugal transfer of ti plasmids from agrobacterium spp. is controlled by a hierarchical regulatory system designed to sense two environmental cues. one signal, a subset of the opines produced by crown gall tumors initiated on plants by the pathogen, serves to induce production of the second, an acyl-homoserine lactone quorum-sensing signal, the quormone, produced by the bacterium itself. this second signal activates trar, and this transcriptional activator induces expression of the tra regulon. ... | 2002 | 11807073 |
| expression of a crown gall biological control phenotype in an avirulent strain of agrobacterium vitis by addition of the trifolitoxin production and resistance genes. | agrobacterium vitis is a causal agent of crown-gall disease. trifolitoxin (tfx) is a peptide antibiotic active only against members of a specific group of alpha-proteobacteria that includes agrobacterium and its close relatives. the ability of tfx production by an avirulent strain of agrobacterium to reduce crown gall disease is examined here. | 2002 | 11882255 |
| pehn, a polygalacturonase homologue with a low hydrolase activity, is coregulated with the other erwinia chrysanthemi polygalacturonases. | erwinia chrysanthemi 3937 secretes an arsenal of pectinolytic enzymes, including at least eight endo-pectate lyases encoded by pel genes, which play a major role in the soft-rot disease caused by this bacterium on various plants. e. chrysanthemi also produces some hydrolases that cleave pectin. three adjacent hydrolase genes, pehv, pehw, and pehx, encoding exo-poly-alpha-d-galacturonosidases, have been characterized. these enzymes liberate digalacturonides from the nonreducing end of pectin. we ... | 2002 | 11976295 |
| a new type iv secretion system promotes conjugal transfer in agrobacterium tumefaciens. | two dna transfer systems encoded by the tumor-inducing (ti) plasmid have been previously identified in agrobacterium tumefaciens. the virb operon is required for the transfer of transferred dna to the plant host, and the trb system encodes functions required for the conjugal transfer of the ti plasmid between cells of agrobacterium. recent availability of the genome sequence of agrobacterium allowed us to identify a third system that is most similar to the virb type iv secretion system of barton ... | 2002 | 12169609 |
| characterization of erwinia amylovora strains using random amplified polymorphic dna fragments (rapds). | the genetic diversity among 16 strains of erwinia amylovora, chosen to represent different host plant origins and geographical regions, was investigated by rapd analysis. one strain of erwinia herbicola and one of agrobacterium vitis were used as outgroups. ninety-eight different rapd fragments were produced by polymerase chain reaction amplification with six different 10-mer primers. rapd banding profiles were found that enabled the erw. amylovora strains to be distinguished from one another. c ... | 1997 | 12455904 |
| induction of sucrose utilization genes from bifidobacterium lactis by sucrose and raffinose. | the probiotic organism bifidobacterium lactis was isolated from a yoghurt starter culture with the aim of analyzing its use of carbohydrates for the development of prebiotics. a sucrose utilization gene cluster of b. lactis was identified by complementation of a gene library in escherichia coli. three genes, encoding a sucrose phosphorylase (scrp), a galr-laci-type transcriptional regulator (scrr), and a sucrose transporter (scrt), were identified by sequence analysis. the scrp gene was expresse ... | 2003 | 12513973 |
| discordant phylogenies within the rrn loci of rhizobia. | it is evident from complete genome sequencing results that lateral gene transfer and recombination are essential components in the evolutionary process of bacterial genomes. since this has important implications for bacterial systematics, the primary objective of this study was to compare estimated evolutionary relationships among a representative set of alpha-proteobacteria by sequencing analysis of three loci within their rrn operons. tree topologies generated with 16s rrna gene sequences were ... | 2003 | 12730157 |
| a luxr homolog, avir, in agrobacterium vitis is associated with induction of necrosis on grape and a hypersensitive response on tobacco. | a tn5 mutant of agrobacterium vitis f2/5 (m1154) differs from the wild-type strain in that it has lost its abilities to cause necrosis on grape and a hypersensitive-like response (hr) on tobacco. the tn5 insertion occurred in an open reading frame (orf) avir that is homologous to genes encoding the luxr family of transcriptional regulators, thereby suggesting that the hr and necrosis are regulated by a quorum-sensing system. fewer n-acyl-homoserine lactone autoinducers were detected in extracts ... | 2003 | 12848431 |
| translation start sequences affect the efficiency of silencing of agrobacterium tumefaciens t-dna oncogenes. | agrobacterium tumefaciens oncogenes cause transformed plant cells to overproduce auxin and cytokinin. two oncogenes encode enzymes that convert tryptophan to indole-3-acetic acid (auxin): iaam (tryptophan mono-oxygenase) and iaah (indole-3-acetamide hydrolase). a third oncogene (ipt) encodes amp isopentenyl transferase, which produces cytokinin (isopentenyl-amp). inactivation of ipt and iaam (or iaah) abolishes tumorigenesis. because adequate means do not exist to control crown gall, we created ... | 2003 | 12972655 |
| microbial synergy via an ethanol-triggered pathway. | we have discovered a microbial interaction between yeast, bacteria, and nematodes. upon coculturing, saccharomyces cerevisiae stimulated the growth of several species of acinetobacter, including, a. baumannii, a. haemolyticus, a. johnsonii, and a. radioresistens, as well as several natural isolates of acinetobacter. this enhanced growth was due to a diffusible factor that was shown to be ethanol by chemical assays and evaluation of strains lacking adh1, adh3, and adh5, as all three genes are inv ... | 2004 | 15082781 |
| agrobacterium rhizogenes galls protein substitutes for agrobacterium tumefaciens single-stranded dna-binding protein vire2. | agrobacterium tumefaciens and agrobacterium rhizogenes transfer plasmid-encoded genes and virulence (vir) proteins into plant cells. the transferred dna (t-dna) is stably inherited and expressed in plant cells, causing crown gall or hairy root disease. dna transfer from a. tumefaciens into plant cells resembles plasmid conjugation; single-stranded dna (ssdna) is exported from the bacteria via a type iv secretion system comprised of virb1 through virb11 and vird4. bacteria also secrete certain vi ... | 2004 | 15126468 |
| identification of an antibacterial compound, benzylideneacetone, from xenorhabdus nematophila against major plant-pathogenic bacteria. | an entomopathogenic bacterium, xenorhabdus nematophila, is known to have potent antibiotic activities to maintain monoxenic condition in its insect host for effective pathogenesis and ultimately for optimal development of its nematode symbiont, steinernema carpocapsae. in this study we assess its antibacterial activity against plant-pathogenic bacteria and identify its unknown antibiotics. the bacterial culture broth had significant antibacterial activity that increased with development of the b ... | 2004 | 15476972 |
| luxr homolog avhr in agrobacterium vitis affects the development of a grape-specific necrosis and a tobacco hypersensitive response. | the luxr homolog avir in agrobacterium vitis strain f2/5 was recently shown to be associated with induction of a hypersensitive response (hr) on tobacco and necrosis on grape plants, indicating that the responses are regulated by quorum sensing. we now report a second luxr homolog, avhr, whose disruption (mutant m1320) results in hr-negative and reduced grape necrosis phenotypes. the deduced avhr protein has characteristic autoinducer binding and dna binding domains and is unique among reported ... | 2005 | 15601702 |
| protein domains and architectural innovation in plant-associated proteobacteria. | evolution of new complex biological behaviour tends to arise by novel combinations of existing building blocks. the functional and evolutionary building blocks of the proteome are protein domains, the function of a protein being dependent on its constituent domains. we clustered completely-sequenced proteomes of prokaryotes on the basis of their protein domain content, as defined by pfam (release 16.0). this revealed that, although there was a correlation between phylogeny and domain content, ot ... | 2005 | 15715905 |
| molecular analysis of the rebeccamycin l-amino acid oxidase from lechevalieria aerocolonigenes atcc 39243. | rebeccamycin, a member of the tryptophan-derived indolocarbazole family, is produced by lechevalieria aerocolonigenes atcc 39243. the biosynthetic pathway that specifies biosynthesis of this important metabolite is comprised of 11 genes spanning 18 kb of dna. a presumed early enzyme involved in elaboration of the rebeccamycin aglycone is encoded by rebo, located at the left-hand region of the reb gene cluster. the deduced protein product, rebo (51.9 kda), is an l-amino acid oxidase (l-aao) that ... | 2005 | 15743957 |
| rhizobial 16s rrna and dnak genes: mosaicism and the uncertain phylogenetic placement of rhizobium galegae. | the phylogenetic relatedness among 12 agriculturally important species in the order rhizobiales was estimated by comparative 16s rrna and dnak sequence analyses. two groups of related species were identified by neighbor-joining and maximum-parsimony analysis. one group consisted of mesorhizobium loti and mesorhizobium ciceri, and the other group consisted of agrobacterium rhizogenes, rhizobium tropici, rhizobium etli, and rhizobium leguminosarum. although bootstrap support for the placement of t ... | 2005 | 15746335 |
| [testing of some grapevine cultivars for the presence of crown gall disease agent and fanleaf and leafroll viruses]. | some rootstocks and scion cultivars grown in ukraine have been tested for the presence of tumorigenic agrobacteria, grapevine fanleaf and grapevine leafroll viruses of the 1st and 3rd serotypes by polymerase chain reaction and enzyme-linked immunosorbent assay. the conditions of polymerase chain reaction were modified in the course of investigations. it was shown that the certified material as well as regular planting material may be infected by the agent of crown gall disease. certified grapevi ... | 2005 | 15765882 |
| a comprehensive update of the sequence and structure classification of kinases. | a comprehensive update of the classification of all available kinases was carried out. this survey presents a complete global picture of this large functional class of proteins and confirms the soundness of our initial kinase classification scheme. | 2005 | 15771780 |
| autoinduction in erwinia amylovora: evidence of an acyl-homoserine lactone signal in the fire blight pathogen. | erwinia amylovora causes fire blight disease of apple, pear, and other members of the rosaceae. here we present the first evidence for autoinduction in e. amylovora and a role for an n-acyl-homoserine lactone (ahl)-type signal. two major plant virulence traits, production of extracellular polysaccharides (amylovoran and levan) and tolerance to free oxygen radicals, were controlled in a bacterial-cell-density-dependent manner. two standard autoinducer biosensors, agrobacterium tumefaciens ntl4 an ... | 2005 | 15838048 |
| development of a reca gene-based identification approach for the entire burkholderia genus. | burkholderia is an important bacterial genus containing species of ecological, biotechnological, and pathogenic interest. with their taxonomy undergoing constant revision and the phenotypic similarity of several species, correct identification of burkholderia is difficult. a genetic scheme based on the reca gene has greatly enhanced the identification of burkholderia cepacia complex species. however, the pcr developed for the latter approach was limited by its specificity for the complex. by ali ... | 2005 | 16000805 |
| novel lectin-like bacteriocins of biocontrol strain pseudomonas fluorescens pf-5. | bacteriocin llpa, produced by pseudomonas sp. strain bw11m1, is a peculiar antibacterial protein due to its homology to mannose-binding lectins mostly found in monocots (a. h. a. parret, g. schoofs, p. proost, and r. de mot, j. bacteriol. 185:897-908, 2003). biocontrol strain pseudomonas fluorescens pf-5 contains two llpa-like genes, named llpa1(pf-5) and llpa2(pf-5). recombinant escherichia coli cells expressing llpa1(pf-5) or llpa2(pf-5) acquired bacteriocin activity and secreted a 31-kda prot ... | 2005 | 16151105 |
| plant-derived transfer dnas. | the transfer of dna from agrobacterium to plant cell nuclei is initiated by a cleavage reaction within the 25-bp right border of ti plasmids. in an effort to develop all-native dna transformation vectors, 50 putative right border alternatives were identified in both plant expressed sequence tags and genomic dna. efficacy tests in a tobacco (nicotiana tabacum) model system demonstrated that 14 of these elements displayed at least 50% of the activity of conventional agrobacterium transfer dna bord ... | 2005 | 16244143 |
| polyphenol oxidase activity expression in ralstonia solanacearum. | sequencing of the genome of ralstonia solanacearum revealed several genes that putatively code for polyphenol oxidases (ppos). to study the actual expression of these genes, we looked for and detected all kinds of ppo activities, including laccase, cresolase, and catechol oxidase activities, in cellular extracts of this microorganism. the conditions for the ppo assays were optimized for the phenolic substrate, ph, and sodium dodecyl sulfate concentration used. it was demonstrated that three diff ... | 2005 | 16269713 |
| rhizobium daejeonense sp. nov. isolated from a cyanide treatment bioreactor. | a polyphasic study was carried out to determine the taxonomic position of two aerobic, cyanide-degrading bacterial strains, designated l61t and l22, which had been isolated from a bioreactor for the treatment of nickel-complexed cyanide. the two isolates exhibited almost identical taxonomic characteristics. phylogenetic analysis inferred from comparative 16s rrna gene sequences indicated that the isolates fall in a sublineage of the genus rhizobium comprising the type strains of rhizobium giardi ... | 2005 | 16280524 |
| rapid and specific identification of four agrobacterium species and biovars using multiplex pcr. | on the basis of 23s rrna gene sequences, 1 universal forward and 4 taxon (species/biovar)-specific reverse primers were designed for multiplex pcr to aid in identification and differentiation of agrobacterium rubi, agrobacterium vitis and agrobacterium biovars 1 and 2. in reactions with dna of 119 bacterial strains belonging to: agrobacterium, allorhizobium, mesorhizobium, rhizobium, sinorhizobium and phyllobacterium, as well as phytopathogenic bacteria representing various genera, the primers d ... | 2006 | 16343837 |
| evaluation of transgenic 'chardonnay' (vitis vinifera) containing magainin genes for resistance to crown gall and powdery mildew. | magainins, short peptides with broad-spectrum antimicrobial activity in vitro, were assayed for their ability to confer resistance to pathogens in transgenic grapevines. embryogenic cell suspensions of 'chardonnay' (vitis vinifera l.) were co-transformed by microprojectile bombardment with a plasmid carrying the npt-ii gene and a second plasmid harboring either a natural magainin-2 (mag2) or a synthetic derivative (msi99) gene. magainin genes and the marker gene were driven by arabidopsis ubiqui ... | 2006 | 16475011 |
| health considerations regarding horizontal transfer of microbial transgenes present in genetically modified crops. | the potential effects of horizontal gene transfer on human health are an important item in the safety assessment of genetically modified organisms. horizontal gene transfer from genetically modified crops to gut microflora most likely occurs with transgenes of microbial origin. the characteristics of microbial transgenes other than antibiotic-resistance genes in market-approved genetically modified crops are reviewed. these characteristics include the microbial source, natural function, function ... | 2005 | 16489267 |
| the agrobacterium vitis t-6b oncoprotein induces auxin-independent cell expansion in tobacco. | among the agrobacterium t-dna genes, rolb, rolc, orf13, orf8, lso, 6b and several other genes encode weakly homologous proteins with remarkable effects on plant growth. the 6b oncogene induces tumors and enations. in order to study its properties we have used transgenic tobacco plants that carry a dexamethasone-inducible 6b gene, dex-t-6b. upon induction, dex-t-6b plants develop a large array of morphological modifications, some of which involve abnormal cell expansion. in the present investigat ... | 2006 | 16507091 |
| regulation of long-chain n-acyl-homoserine lactones in agrobacterium vitis. | homologs of quorum-sensing luxr and luxi regulatory genes, avsr and avsi, were identified in agrobacterium vitis strain f2/5. compared to other luxi proteins from related species, the deduced avsi shows the greatest identity to sini (71%) from sinorhizobium meliloti rm1021. avsr possesses characteristic autoinducer binding and helix-turn-helix dna binding domains and shares a high level of identity with sinr (38%) from rm1021. site-directed mutagenesis of avsr and avsi was performed, and both ge ... | 2006 | 16513747 |
| physical, chemical, developmental, and genetic factors that modulate the agrobacterium-vitis interaction. | tumor formation in vitis species and hybrids, incited by agrobacterium tumefaciens, was altered by chemical, physical, developmental, and genetic variables. knowledge of the effect of these variables was used to develop a stringent in vitro assay system to select parents for a study of genetic factors that modulate tumor formation. tumor formation was reduced by short day preconditioning of assay plants and by inoculation of the morphological apex of isolated stem segments. pretreatment of plant ... | 1991 | 16668140 |
| construction of physical map and mapping of chromosomal virulence genes of the biovar 3 agrobacterium (rhizobium vitis) strain k-ag-1. | most plant pathogenic agrobacterium strains have been classified into three biovars, "biovar 1 (a. tumefaciens; rhizobium radiobacter), biovar 2 (a. rhizogenes; r. rhizogenes) and biovar 3 (a. vitis; r. vitis)". the bacteria possess diverse types of genomic organization depending on the biovar. previous genomic physical maps indicated difference in location of rdna and chromosomally-coded virulence genes between biovar 1 and 2 genomes. in order to understand biovar 3 genome and its evolution in ... | 2006 | 17283382 |
| cell-cell communication in the plant pathogen agrobacterium tumefaciens. | the plant pathogen agrobacterium tumefaciens induces the formation of crown gall tumours at wound sites on host plants by directly transforming plant cells. this disease strategy benefits the bacteria as the infected plant tissue produces novel nutrients, called opines, that the colonizing bacteria can use as nutrients. almost all of the genes that are required for virulence, and all of the opine uptake and utilization genes, are carried on large tumour-inducing (ti) plasmids. the observation mo ... | 2007 | 17360279 |
| novel scar primers for specific and sensitive detection of agrobacterium vitis strains. | an agrobacterium vitis-specific dna fragment (pavs3) was generated from pcr polymorphic bands amplified by primer urp 2r. a. vitis specificity of this fragment was confirmed by southern hybridization with genomic dna from different agrobacterium species. sequence-characterized amplified region (scar) markers were developed for a. vitis specific detection, using 24-mer oligonucleotide primers designed from the flanking ends of the 670bp insert in pavs3. the scar primers amplified target sequences ... | 2009 | 17467252 |
| study of the mode of action of a polygalacturonase from the phytopathogen burkholderia cepacia. | we have recently isolated and heterologously expressed bcpeh28a, an endopolygalacturonase from the phytopathogenic gram-negative bacterium burkholderia cepacia. endopolygalacturonases belong to glycoside hydrolase family 28 and are responsible for the hydrolysis of the non-esterified regions of pectins. the mode of action of bcpeh28a on different substrates has been investigated and its enzymatic mechanism elucidated. the hydrolysis of polygalacturonate indicates that bcpeh28a is a non-processiv ... | 2007 | 17627609 |
| glycerate kinase of the hyperthermophilic archaeon thermoproteus tenax: new insights into the phylogenetic distribution and physiological role of members of the three different glycerate kinase classes. | the presence of the branched entner-doudoroff (ed) pathway in two hyperthermophilic crenarchaea, the anaerobe thermoproteus tenax and the aerobe sulfolobus solfataricus, was suggested. however, so far no enzymatic information of the non-phosphorylative ed branch and especially its key enzyme - glycerate kinase - was available. in the t. tenax genome, a gene homolog with similarity to putative hydroxypyruvate reductase/glycerate dehydrogenase and glycerate kinase was identified. | 2007 | 17764545 |
| the plant pathogen pantoea ananatis produces n-acylhomoserine lactone and causes center rot disease of onion by quorum sensing. | a number of gram-negative bacteria have a quorum-sensing system and produce n-acyl-l-homoserine lactone (ahl) that they use them as a quorum-sensing signal molecule. pantoea ananatis is reported as a common colonist of wheat heads at ripening and causes center rot of onion. in this study, we demonstrated that p. ananatis sk-1 produced two ahls, n-hexanoyl-l-homoserine lactone (c6-hsl) and n-(3-oxohexanoyl)-l-homoserine lactone (3-oxo-c6-hsl). we cloned the ahl-synthase gene (eani) and ahl-recept ... | 2007 | 17827290 |
| an oncoprotein from the plant pathogen agrobacterium has histone chaperone-like activity. | protein 6b, encoded by t-dna from the pathogen agrobacterium tumefaciens, stimulates the plant hormone-independent division of cells in culture in vitro and induces aberrant cell growth and the ectopic expression of various genes, including genes related to cell division and meristem-related class 1 knox homeobox genes, in 6b-expressing transgenic arabidopsis thaliana and nicotiana tabacum plants. protein 6b is found in nuclei and binds to several plant nuclear proteins. here, we report that 6b ... | 2007 | 17890376 |
| the quorum-sensing system avsr-avsi regulates both long-chain and short-chain acyl-homoserine lactones in agrobacterium vitis e26. | agrobacterium vitis strain e26 is a nonpathogenic bacterium isolated from grape crown gall. in this study, the identification of a luxr-luxi type quorum-sensing system in strain e26 is reported. this system is involved in the induction of hypersensitive response on tobacco, but not its biocontrol activity. the deduced components avsi(e26) and avsr(e26) show the greatest similarity to avsi(f2/5) and avsr(f2/5), respectively from a. vitis strain f2/5. the mutant in avsi(e26) abolished the producti ... | 2008 | 17906938 |
| variation of 16s-23s internally transcribed spacer sequence and intervening sequence in rdna among the three major agrobacterium species. | we analyzed 16s-23s internally transcribed spacer (its) and neighboring sequences among 37 strains belonging to the three major pathogenic agrobacterium species, in order to know variation in each species and to develop a simple discrimination method. number of its size variation was 9, 4, and 7 in agrobacterium tumefaciens, agrobacterium vitis, and agrobacterium rhizogenes, respectively. the its sequence of most strains in each species was distinguishable from that of the other two species. the ... | 2009 | 17997085 |
| glycerate 2-kinase of thermotoga maritima and genomic reconstruction of related metabolic pathways. | members of a novel glycerate-2-kinase (gk-ii) family were tentatively identified in a broad range of species, including eukaryotes and archaea and many bacteria that lack a canonical enzyme of the gark (gk-i) family. the recently reported three-dimensional structure of gk-ii from thermotoga maritima (tm1585; pdb code 2b8n) revealed a new fold distinct from other known kinase families. here, we verified the enzymatic activity of tm1585, assessed its kinetic characteristics, and used directed muta ... | 2008 | 18156253 |
| glycerate 2-kinase of thermotoga maritima and genomic reconstruction of related metabolic pathways. | members of a novel glycerate-2-kinase (gk-ii) family were tentatively identified in a broad range of species, including eukaryotes and archaea and many bacteria that lack a canonical enzyme of the gark (gk-i) family. the recently reported three-dimensional structure of gk-ii from thermotoga maritima (tm1585; pdb code 2b8n) revealed a new fold distinct from other known kinase families. here, we verified the enzymatic activity of tm1585, assessed its kinetic characteristics, and used directed muta ... | 2008 | 18156253 |
| a novel gdp-dependent pyruvate kinase isozyme from toxoplasma gondii localizes to both the apicoplast and the mitochondrion. | we previously reported a cytosolic pyruvate kinase (ec 2.7.1.40) from toxoplasma gondii (tgpyki) that differs from most eukaryotic pyruvate kinases in being regulated by glucose 6-phosphate rather than fructose 1,6-diphosphate. another putative pyruvate kinase (tgpykii) was identified from parasite genome, which exhibits 32% amino acid sequence identity to tgpyki and retains pyruvate kinase signature motifs and amino acids essential for substrate binding and catalysis. whereas tgpyki is most clo ... | 2008 | 18326043 |
| the effect of chromosome geometry on genetic diversity. | although organisms with linear chromosomes must solve the problem of fully replicating their chromosome ends, this chromosome configuration has emerged repeatedly during bacterial evolution and is evident in three divergent bacterial phyla. the benefit usually ascribed to this topology is the ability to boost genetic variation through increased recombination. but because numerous processes can impact linkage disequilibrium, such an effect is difficult to assess by comparing across bacterial taxa ... | 2008 | 18493068 |
| crystallization, x-ray diffraction analysis and preliminary structure determination of the polygalacturonase peha from agrobacterium vitis. | polygalacturonases are pectate-degrading enzymes that belong to glycoside hydrolase family 28 and hydrolyze the alpha-1,4 glycosidic bond between neighboring galacturonasyl residues of the homogalacturonan substrate. the acidic polygalacturonase peha from agrobacterium vitis was overexpressed in escherichia coli, where it accumulated in the periplasmic fraction. it was purified to homogeneity via a two-step chromatography procedure and crystallized using the hanging-drop vapour-diffusion techniq ... | 2008 | 18607098 |
| the genome of burkholderia cenocepacia j2315, an epidemic pathogen of cystic fibrosis patients. | bacterial infections of the lungs of cystic fibrosis (cf) patients cause major complications in the treatment of this common genetic disease. burkholderia cenocepacia infection is particularly problematic since this organism has high levels of antibiotic resistance, making it difficult to eradicate; the resulting chronic infections are associated with severe declines in lung function and increased mortality rates. b. cenocepacia strain j2315 was isolated from a cf patient and is a member of the ... | 2009 | 18931103 |
| the genome of burkholderia cenocepacia j2315, an epidemic pathogen of cystic fibrosis patients. | bacterial infections of the lungs of cystic fibrosis (cf) patients cause major complications in the treatment of this common genetic disease. burkholderia cenocepacia infection is particularly problematic since this organism has high levels of antibiotic resistance, making it difficult to eradicate; the resulting chronic infections are associated with severe declines in lung function and increased mortality rates. b. cenocepacia strain j2315 was isolated from a cf patient and is a member of the ... | 2009 | 18931103 |
| effect of wound position, auxin, and agrobacterium vitis strain f2/5 on wound healing and crown gall in grapevine. | abstract agrobacterium vitis is the causal agent of crown gall disease in grapevine, which can be severe in many regions worldwide. vitis vinifera cultivars are highly susceptible to freeze injury, providing the wounds necessary for infection by a. vitis. wound position in relation to the uppermost bud of cuttings was determined to be important in tumor development. inoculated wounds below buds developed tumors, whereas wounds opposite the bud did not, implying that indole-3-aectic acid flow con ... | 2005 | 18943037 |
| biological control of crown gall of grapevine, rose, and tomato by nonpathogenic agrobacterium vitis strain var03-1. | a nonpathogenic strain of agrobacterium vitis var03-1 was tested as a biological control agent for crown gall of grapevine (vitis vinifera). when roots of grapevine, rose (rose multiflora), and tomato (lycopersicon esculentum) were soaked in a cell suspension of antagonists before planting in soil infested with tumorigenic a. vitis, a. rhizogenes, and a. tumefaciens, respectively, treatment with var03-1 significantly reduced the number of plants with tumors and disease severity in the three plan ... | 2008 | 18943411 |
| mutations that affect agrobacterium vitis-induced grape necrosis also alter its ability to cause a hypersensitive response on tobacco. | abstract tn5-induced mutations in agrobacterium vitis f2/5 resulted in both altered grape necrosis and tobacco leaf panel collapse phenotypes, suggesting that the underlying mechanisms of the reactions are related. the reaction on tobacco resembles the classical hypersensitive response (hr) caused by several plant pathogenic bacteria in that it is observable within 14 h, is inhibited by treatment of plants with metabolic inhibitors, and results in the inability to recover the pathogen from the n ... | 2001 | 18944123 |
| biological control of grape crown gall by strain f2/5 is not associated with agrocin production or competition for attachment sites on grape cells. | abstract agrocin-minus mutants of nontumorigenic agrobacterium vitis strain f2/5 controlled grape crown gall as well as the wild-type strain, indicating that agrocin is not a major factor in the mechanism of biological control. relative levels of attachment to grape cells by tumorigenic and biocontrol strains were also measured. attachment of tumorigenic strains (cg49 and k306) and biological control strains (f2/5 and agrocin-minus mutant 1077) was often reduced when mixtures of the strains were ... | 1997 | 18945092 |
| a gene cluster in agrobacterium vitis homologous to polyketide synthase operons is associated with grape necrosis and hypersensitive response induction on tobacco. | here, we identify a cluster of eight genes on chromosome 2 of agrobacterium vitis that is associated with the ability of the bacterium to cause a hypersensitive response on tobacco and a necrosis of grape shoot explants. three of these genes share a high level of structural and sequence similarity to clusters of genes in other bacteria that encode the enzymes for biosynthesis of polyketides and long-chain polyunsaturated fatty acids. no similar gene clusters were discovered in sequenced genomes ... | 2008 | 19054098 |
| construction of disarmed ti plasmids transferable between escherichia coli and agrobacterium species. | agrobacterium-mediated plant transformation has been used widely, but there are plants that are recalcitrant to this type of transformation. this transformation method uses bacterial strains harboring a modified tumor-inducing (ti) plasmid that lacks the transfer dna (t-dna) region (disarmed ti plasmid). it is desirable to develop strains that can broaden the host range. a large number of agrobacterium strains have not been tested yet to determine whether they can be used in transformation. in o ... | 2009 | 19181833 |
| identification of an rsh gene from a novosphingobium sp. necessary for quorum-sensing signal accumulation. | the stringent response is a mechanism by which bacteria adapt to environmental stresses and nutritional deficiencies through the synthesis and hydrolysis of (p)ppgpp by rela/spot enzymes. alphaproteobacteria and plants contain a single rsh enzyme (named for rela/spot homolog) that is bifunctional. here we report the identification of a new species of bacteria belonging to the genus novosphingobium and characterization of an rsh mutation in this plant tumor-associated isolate. isolate rr 2-17, fr ... | 2009 | 19201802 |
| characterization of the polyoxin biosynthetic gene cluster from streptomyces cacaoi and engineered production of polyoxin h. | a gene cluster (pol) essential for the biosynthesis of polyoxin, a nucleoside antibiotic widely used for the control of phytopathogenic fungi, was cloned from streptomyces cacaoi. a 46,066-bp region was sequenced, and 20 of 39 of the putative open reading frames were defined as necessary for polyoxin biosynthesis as evidenced by its production in a heterologous host, streptomyces lividans tk24. the role of polo and pola in polyoxin synthesis was demonstrated by in vivo experiments, and their fun ... | 2009 | 19233844 |