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J Altenbuchner

Publications and source records attributed to J Altenbuchner.

59 records · Page 4Linked to original sources

Evidence for a plasmid in a methanogenic bacterium.

Among 15 strains of methanogens, one plasmid, pMP1, was identified in the new coccoid isolate PL-12/M. It could not be detected in the cleared lysate, but it was detected in the viscous pellet. The plasmid had a molecular weight of ca. 4.6 x 10(6). A restriction enzyme cleavage map of the cloned plasmid was derived.

Base Sequence↗

The tetracycline resistance transposons Tn1721 and Tn1771 have three 38-base-pair repeats and generate five-base-pair direct repeats.

The 10.7 kilobase (kb) tetracycline resistance transposons Tn1721 and Tn1771, isolated from disparate sources, are completely homologous on the basis of heteroduplex analyses. Both transposable elements are capable of forming multiple duplications of a 5.3 kb portion encompassing the resistance genes (tet region). A model accounting for both, recA-independent translocation and recA-dependent amplification, postulates two direct and one inverted repeat as essential constituents of the transposons. DNA sequence analyses of Tn1721 and Tn1771 have substantiated this model. They demonstrated three identical 38 base pair repeats identically in both transposons dividing them into a "minor transposon" and a tet region. Identical sequences of at least 87 base pairs providing recombination "hot spots" for gene duplication have been found at the ends of the repetitious tet region. Translocation of Tn1721 and Tn1771 generates five base pair direct repeats at the respective sites of insertion. On the basis of the heteroduplex molecules and sequences analyzed the two transposons are identical.

Base Sequence↗