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P Starlinger

Publications and source records attributed to P Starlinger.

At least 55 records · Page 3Linked to original sources

IS4 at its chromosomal site in E. coli K12.

IS4 DNA has been isolated in pure form. Hybridization of this DNA against restricted DNA of several E. coli K12 strains by Southern's blotting technique has shown that, in most strains, only one copy of IS4 is present. Though the restriction fragments around this site differ in size, IS4 can be shown always to be located at the same site. In one strain, one additional copy has been found in a new location. In this strain, IS4 in its original location has been retained.

Chromosome Mapping↗

IS4 is found between eleven or twelve base pair duplications.

Three mutations caused by the integration of IS4 in galT in both possible orientations were shown by DNA sequence analysis to be integrated between a duplication of eleven base pairs of gene galT. IS4 has been cloned from its single position on the E. coli K12 chromosome. Here, 12 base pairs are duplicated adjacent to IS4. This sequence is unrelated to the duplicated sequence in galT.

Base Sequence↗

Close vicinity of IS1 integration sites in the leader sequence of the gal operon of E. coli.

Four insertions of IS1 in the leader sequence of the gal operon of E. coli have been analysed. Two of them occur at the same position, but in opposite orientations. The other two are inserted one nucleotide to one side and four nucleotides to the other side, respectively. In each case, nine base pairs of the leader sequence of the gal operon are duplicated directly, and are found flanking the termini of IS1 at its junction with the gal operon. These repeated sequences differ from each other as expected from the different insertion sites.

Base Sequence↗

Nomenclature of transposable elements in prokaryotes.

Transposable elements are defined as specific DNA segments that can repeatedly insert into a few or many sites in a genome. They are classified as simple IS elements, more complex Tn transposons and self-replicating episomes. Definitions and nomenclature rules for these three classes of prokaryotic transposable elements are specified.

Cells↗

[IS-elements and transposons: new linkage of genes within bacteria (author's transl)].

IS-Elements are unique DNA sequences occurring in the DNA of E. coli and its chromosomes. They can be transposed within or between chromosomes in the same cell. Integration into a gene causes mutations and polar effects on adjacent genes. IS-Elements are integration sites for plasmids into chromosomes. IS-Elements also serve as parts of transposons (DNA structures capable to be transposed from one chromosome to another and carrying a gene for the resistance to an antibiotic or heavy metals).

Base Sequence↗

The isolation of IS1 and IS2 DNA.

DNA of the IS-elements IS1 and IS2 was prepared by digestion of appropriate heteroduplex molecules with endonuclease S1, followed by sucrose gradient centrifugation or gel electrophoresis. The material obtained is homogeneous with regard to size. The length of IS1 DNA is 820 +/- 65 nucleotides, the length of IS2 DNA is 1,350 +/- 70 nucleotides. IS1 DNA is not cleaved by the restriction endonucleases Eco R1, Hind II or Hind III. IS2 DNA is cleaved once by each of the two latter enzymes. The buoyand density determined by equilibrium centrifugation of Hg-complexes in Cs2so4 corresponds to a GC content of approximately 50%. Labelling with polynucleotide kinase indicates that both IS DNA's have a guanosyl residue at both of their 5'-termini.

Centrifugation, Density Gradient↗