A coupled transcription-translation system was isolated from A. tumefaciens. Expression of plasmids pBR322 and pKT212 from E.coli, cloned fragments of Ti plasmid (plasmids pSS155 and pSS156) and Ti plasmid derivatives pAL2802, pAL2811, pAL2821 and pAL2832 was analysed in an A. tumefaciens cell-free system and compared with their expression in an E.coli cell-free system. New proteins of 41K and ...

We describe here a new strategy of fragment preparation for sequencing procedures using endlabelled DNA fragments as substrates (2,3) which is directly applicable to DNA fragments cloned into the Pst I site of pBR322, or in modified form, to inserts into the BamH I or Sal I site of the same plasmid. Ordered sets of subclones of predetermined overlap are are generated. These can be sequenced dir...

A library of B. thuringiensis DNA has been prepared by using the plasmid pBR322 as a cloning vehicle and E. coli as a host cell. By screening this collection with specific probes, 17 clones were identified whose hybrid plasmids contain rRNA genes of B. thuringiensis. Several of these plasmids have been mapped with restriction endonucleases and by DNA-RNA hybridization. By using maps of overlapp...

Relief of an auxotrophic requirement for uridine in Aspergillus nidulans strain G191 has been achieved by transformation with a segment of Neurospora crassa DNA containing the corresponding gene coding for orotidine-5'-phosphate decarboxylase. The mitotic stability of such transformants suggests that the DNA has integrated into the genome. Southern hybridisation analysis of DNA isolated from tr...

Cobalt(II)  complexes of isonicotinoyl hydrazones of two series of ligands have been synthesized and characterized on the basis of elemental analyses, molar conductance, magnetic moment, mass, IR, UV spectral data. Electrochemical behavior of ligands and complexes has been investigated by using cyclic voltammetry. Cyclic voltammetric studies reveal that the oxidation/reduct...

High resolution melting profiles of four linearised plasmids (pUC9, pGV403, pHP2, and pBR322) were recorded by means of UV absorbance vs. temperature scanning. The set of transitions obtained for each plasmid are compared to each other and to the transitions obtained for their excised particular antibiotica resistance gene. It can be shown that each gene leaves a characteristic mark on the melt...

With one exception, all spiroplasma strains examined contained extrachromosomal DNA, most of which was in the form of covalently closed circular plasmids. One plasmid, pIJ2000, carried by Spiroplasma citri strain ASP-1, was purified and characterized and used to probe for related plasmids in other strains. Unsuccessful attempts were made to clone pIJ2000 into Escherichia coli using the vectors ...

Tertiary structure changes in plasmid DNA, induced by ethidium bromide intercalation, have been observed in aqueous solutions by the use of an atomic force microscope. A relaxed closed circular pBR322 molecule became a positively supercoiled complex on the drug binding. The supercoiling always resulted in an interwound (or a plectonemic) form, but never a solenoidal (or a toroidal) form. A quan...