ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    facet.materialart.
    Unknown
    Genetic and functional analysis of the nodulation region of the Rhizobium leguminosarum Sym plasmid pRL1JI (1985)
    Springer
    Details
    Publication Date: 1985-12-01
    Print ISSN: 0302-8933
    Electronic ISSN: 1432-072X
    Topics: Biology
    Published by Springer
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 2
    Electronic Resource
    Electronic Resource
    Genetic and functional analysis of the nodulation region of the Rhizobium leguminosarum Sym plasmid pRL1JI (1985)
    Springer
    Archives of microbiology 143 (1985), S. 225-232 
    Details
    ISSN: 1432-072X
    Keywords: Rhizobium leguminosarum ; Nodulation mutants ; Hair curling ; Infection thread ; Sym plasmid ; Complementation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Thirty Tn5- or Tn1831-induced nodulation (nod) mutants of Rhizobium leguminosarum were examined for their genetic and symbiotic properties. Thirteen mutants contained a deletion in Sym plasmid pRL1JI. These deletions cover the whole nod region and are 50 kb in size. All remaining seventeen mutations are located in a 6.6 kb EcoRI nod fragment of the Sym plasmid. Mutations in a 3.5 kb part on the right hand side of this 6.6 kb fragment completely prevent nodulation on Vicia sativa. All mutants in this 3.5 kb area are unable to induce marked root hair curling and thick and short roots. Mutations in a 1.5 kb area on the left hand side of the 6.6 kb nod fragment generate other symbiotic defects in that nodules are only rarely formed and only so after a delay of several days. Moreover, infection thread formation is delayed and root hair curling is more excessive than that caused by the parental strain. Their ability to induce thick and short roots is unaltered. Mutations in this 1.5 kb region are not complemented by pRmSL26, which carries nod genes of R. meliloti, whereas mutations in the 3.5 kb region are all complemented by pRmSL26.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00411240
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Analysis of the major inducers of the Rhizobium nodA promoter from Vicia sativa root exudate and their activity with different nodD genes (1989)
    Springer
    Plant molecular biology 13 (1989), S. 175-188 
    Details
    ISSN: 1573-5028
    Keywords: Rhizobium ; nodA promoter ; flavonoid inducers ; root exudate ; Vicia sativa ; nodD
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Root exudate of Vicia sativa contains 7 inducers for the nodA promoter of Rhizobium leguminosarum biovar viciae. Six of these inducers are flavanones. One inducer was identified as 3,5,7,3′-tetrahydroxy-4′-methoxyflavanone, and a second inducer most likely is 7,3′-dihydroxy-4′-methoxyflavanone. The inducing activity of these compounds and the other inducers depends on the nodD gene present in the test strains, which orginated either from R. leguminosarum biovars viciae or trifolii, or from R. meliloti. Three inducers are ‘common’, three others almost exclusively induce the nodA promoter in the presence of the R. leguminosarum biovar viciae nodD gene, and the last one is active with the noD genes of either R. leguminosarum biovar viciae or that of R. meliloti. Testing of a large number of flavonoids revealed two classes of structural features required for inducing ability: (i) features required for induction in general, and (ii), features restricting the inducing ability to (a) specific nodD gene(s). These features are discussed in relation to current models of the process of nodD-mediated transcription activation of the inducible nod genes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00016136
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Localization of functional regions of the Rhizobium nodD product using hybrid nodD genes (1989)
    Springer
    Plant molecular biology 12 (1989), S. 59-73 
    Details
    ISSN: 1573-5028
    Keywords: autoregulation ; flavonoid independent transcription ; flavonoid specificity ; gene regulation ; nodD gene ; Rhizobium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The flavonoid-inducible nod promoters of Rhizobium are positively regulated by the nodD gene which is highly conserved in various Rhizobium species. The nodD gene are functionally different in (i) their response to various exogenously added flavonoid inducers, (ii) the extent to which they mediate the activation of the flavonoid-inducible promoters, and (iii) the extent to which they repress their own constitutive transcription. In order to localize the regions of the nodD product which determine these differences, two series of nodD hybrid genes have been constructed. In one series the 5′ moiety is derived from the R. meliloti nodD1 gene and the 3′ moiety from the R. trifolii nodD gene. In the other series, the origins of the nodD moieties are reversed. Two regions of the nodD product appeared to be involved in autoregulation and it was also shown that the nodD promoters differ in their susceptibility to autoregulation. Many regions, dispersed over the entire nodD product, are involved in the specificity of activation by flavonoids. Several hybrid nodD genes were characterized which activate transcription with novel inducers. Furthermore, two classes of hybrid nodD genes were found from which the activation characteristics differ completely from those of the parental nodD genes. The first class activates the nodABCIJ promoter to the maximum level in the absence of flavonoid inducer. This level can no longer be influenced, positively or negatively, by the presence of (iso-)flavonoids. With the second class of hybrids, activation of the nodABCIJ promoter, even in the presence of flavonoid inducers, is no longer possible.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00017448
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Additional nodulation genes on the Sym plasmid of Rhizobium leguminosarum biovar viciae (1989)
    Springer
    Plant molecular biology 13 (1989), S. 163-174 
    Details
    ISSN: 1573-5028
    Keywords: Rhizobium leguminosarum biovar viciae ; nodulation genes ; nodL ; transcription unit ; infection thread
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A Rhizobium leguminosarum biovar viciae strain lacking a 40 kb DNA region of the Sym plasmid pRL1IJ to the left (3′ side) of gene nodE failed to nodulate Vicia sativa plants. Therefore this DNA region was investigated for the presence of additional nodulation genes. Complementation experiments indicated that the DNA region to the left (3′ side) of nodE is functionally homologous between R. leguminosarum bv. viciae and R. leguminosarum bv. trifolii. In this DNA region, three nodulation genes were identified, nodT, nodM and nodL. TnphoA insertions in the nodT gene, about 4.5 kb to the left of nodE, lead to a delay in nodulation on Trifolium subterraneum, but not on V. sativa plants. TnphoA insertions in gene nodM have no detectable influence on nodulation. Finally, TnphoA insertions in the nodL gene affected nodulation so that only rarely nodules were induced on the inoculated plants. The nucleotide sequence of this gene is presented. On the basis of the sequence a membrane integrated protein is predicted with a molecular weight of 20.1 kDa. Microscopical analysis of the infection process by nodL mutants indicate a role for nodL in maintaining the stability of the infection thread. Experiments using transcriptional lacZ fusions suggest that nodL belongs to the same transcriptional unit as nodF,E. Very low expression of nodL seems to be sufficient for biological activity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00016135
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Promoters in the nodulation region of the Rhizobium leguminosarum Sym plasmid pRL1JI (1987)
    Springer
    Plant molecular biology 9 (1987), S. 27-39 
    Details
    ISSN: 1573-5028
    Keywords: Rhizobium leguminosarum ; nodulation region ; expression of nodulation genes ; nodulation promoters ; naringenin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A region of 16.8 kb of the Sym(biosis) plasmid pRL1JI of Rhizobium leguminosarum, consisting of the established 9.7 kb nodulation region which confers nodulation ability on Vicia hirsuta and a region of 7.1 kb which appeared to be necessary for nodulation on V. sativa and Trifolium subterraneum, was subcloned as fragments of maximally 2.5 kb in a newly developed IncQ transcriptional fusion vector. The expression of these fragments was studied in Rhizobium. One constitutive promoter, pr.nodD, and three plant-exudate inducible promoters were found, namely the known pr.nodA and pr.nodF as well as a new promoter designated pr.nodM. The latter promoters were localized within 114 bp, 330 bp and 630 bp respectively and they regulate the transcription of the operons nodA, B, C, I, J, nodF, E and of an operon of at least 2.5 kb located in the 7.1 kb region. Induction of the three inducible operons required plant exudate and a functional nodD product. The flavanone naringenin could replace plant exudate. Each of the three inducible promoters contained a nod-box. A consensus for the nod-box sequence, based on known sequences, is proposed. The 114 bp fragment which contains pr.nodA activity was used to localize pr.nodA by means of deletion mapping. The fragment which appeared necessary for complete pr.nodA activity is 72 bp in size, contains the complete nod-box and in addition a region of 21 bp downstream of the nod-box, in which the loosely conserved sequence AT(T)AG appears to be important for promoter activity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00017984
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Vegetative recombination of bacteriophage Mu-1 in Escherichia coli (1972)
    Springer
    Molecular genetics and genomics 116 (1972), S. 40-46 
    Details
    ISSN: 1617-4623
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Twenty-two amber mutants of the thermoinducible mutator phage Mu-c4ts were isolated. These mutants fall into 11 complementation groups. The data obtained by crossing these amber mutants suggest that bacteriophage Mu-1 has a linear vegetative linkage map. In a recombination deficient host of the RecA type the recombination frequencies are extremely low, indicating that Mu-1, in contrast to many other E. coli phages, is dependent on the recombination system of its host. With λ as a helper phage, recombination between Mu phages in a RecA host is restored to about 1/3 of the frequency in a Rec+ host. Although Mu-1 is able to integrate efficiently into the chromosome of a RecA strain, it seems that its integration system does not contribute to vegetative recombination. The survival of UV-irradiated Mu-1 was measured on different radiation sensitive mutants of E. coli. The survival on a UvrB strain was very low as compared to the wild-type; the survival on a RecA strain was almost the same as on the wild-type.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00334258
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Transcription of bacteriophage Mu (1974)
    Springer
    Molecular genetics and genomics 135 (1974), S. 327-337 
    Details
    ISSN: 1617-4623
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary It has previously been shown that the transcription of Mu is asymmetric and takes place on the heavy DNA strand (Bade, 1972; Wijffelman et al., 1974). The direction of transcription of Mu has now been determined by RNA-DNA hybridizations between purified Mu-RNA and the separated strands of λ-Mu hybrid phages. The direction of transcription is from the c-gene (immunity gene) end of the heavy strand to the β-end (immunity distal end) (Fig. 1). Thermo-inducible, defective Mu lysogens, in which the prophage is deleted from the β-end, have a normal early transcription pattern, but the increase of RNA at later times is absent. A defective lysogen, which contains only the immunity gene c and the genes A and B, still has an early transcription pattern similar to that of the wild-type. Therefore, we conclude that the early RNA is transcribed from that region of the Mu genome. The early Mu-RNA synthesis is negatively regulated with a minimum rate of transcription at 9 minutes after induction. Before the onset of the late RNA synthesis, at about 22 minutes there is a rather long period in which the rate of Mu-RNA synthesis slowly increases. Using DNA strands of λ-Mu hybrids which contain only that part of the Mu-DNA on which the early RNA synthesis takes place, we have determined that during the first half in the intermediate phase only early genes are transcribed. The amount of Mu-RNA synthesized by a Mu prophage carrying the X-mutation, which influences the excision of Mu, is greatly reduced. Negative regulation of early transcription occurs normally in this mutant.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00271147
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Kinetics of Mu DNA synthesis (1977)
    Springer
    Molecular genetics and genomics 151 (1977), S. 169-174 
    Details
    ISSN: 1617-4623
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Mu specific DNA synthesis starts at 10 min after infection. All essential amber mutants of Mu were tested for the ability to replicate in a non permissive host. Except for the amber mutants A and B, which were already known to be blocked in Mu DNA synthesis (Wijffelman et al., 1974), all the other mutants showed normal Mu DNA replication. Using mitomycin C-treated cells Mu DNA synthesis was found to start at about 20 min after induction. However using the much more sensitive method of DNA-RNA hybridization, it was found that the DNA synthesis starts already at 10 min after induction, and that at 20 min after induction about 7 copies of the Mu DNA are present per cell.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00338691
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    On the control of transcription of bacteriophage Mu (1974)
    Springer
    Molecular genetics and genomics 131 (1974), S. 85-96 
    Details
    ISSN: 1617-4623
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The transcription pattern of bacteriophage Mu has been studied with the use of Mu-1 cts62, a thermo-inducible derivative of wild-type Mu. The rate of transcription at various times after induction was measured by pulse-labeling the RNA during synthesis and determining the fraction of Mu-specific RNA by hybridization with the separated strands of Mu-DNA. Transcription was found to take place predominantly from the heavy strand of Mu-DNA, as was found previously by Bade (1972). A study of the kinetics of this process revealed four phases. Initially after the induction the rate of transcription increases and reaches a maximum after four minutes. In the second phase during five minutes the rate falls down. During the third phase, up to 25 minutes after induction, the rate of transcription rises slowly, followed by a very rapid increase in the final phase, at the end of the lytic cycle. Phage Mu can be integrated in the host chromosome in two opposite orientations. The strand specificity, rate and time-course of transcription appeared not to be influenced by the orientation. The presence of chloramphenicol during the induction of the phage does not have an effect on the initial phase of transcription, but it prevents the decrease in the second phase. This suggests that in the early phase a Mu-specific protein is synthesized which acts as a negative regulator of trancription. In non-permissive strains, lysogenic for a phage with an amber mutation in gene A or B, the transcription during the first and the second phase is the same as with wild-type phage; in the third phase, however, there is much less transcription than with wild type phage, whereas in the final phase the increase of the transcription rate is completely absent. Control experiments showed that DNA synthesis does not take place when a non-permissive strain is infected with a phage with an amber mutation in gene A or B. Therefore we conclude that the products of the genes A and B are required, directly or indirectly, for the autonomous replication of phage DNA. Since these amber mutants are also impaired in the integration process, we conclude that the genes A and B code for regulator proteins with a crucial role in the development of bacteriophage Mu.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00266145
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...