Learn More
Ti plasmid mutants derived from Agrobacterium tumefaciens strain Ach5 that induce tumors of abnormal morphology have been analyzed. On tobacco, A. tumefaciens mutant strain LBA4060 induces tumors that specifically give rise to shoots. Shoots continue to grow from in vitro cultured bacteria-free tumor tissue derived from such tumors. The mutant character is(More)
The UvrB-DNA preincision complex is a key intermediate in the repair of damaged DNA by the UvrABC endonuclease from Escherichia coli. DNaseI footprinting of this complex on DNA with a cis-[Pt(NH3)2[d(GpG)-N7(1),N7(2)]] adduct provided global information on the protein binding site on this substrate [Visse, R., et al. (1991) J. Biol. Chem. 266, 7609-7617].(More)
It is generally accepted that the damage recognition complex of nucleotide excision repair in Escherichia coli consists of two UvrA and one UvrB molecule, and that in the preincision complex UvrB binds to the damage as a monomer. Using scanning force microscopy, we show here that the damage recognition complex consists of two UvrA and two UvrB subunits,(More)
From the start of the first primitive life forms on earth ultraviolet (UV) light has been a seriously threatening factor. UV light is absorbed by the DNA causing several types of damage that can interfere with transcription and replication. In bacteria a number of different repair mechanisms have evolved to repair these UV-induced lesions. These mechanisms(More)
Nucleotide excision repair removes damages from the DNA by incising the damaged strand on the 3' and 5' sides of the lesion. In Escherichia coli, the two incisions are made by the UvrC protein, which consists of two functional halves. The N-terminal half contains the catalytic site for 3' incision and the C-terminal half contains the residues involved in 5'(More)
Nucleotide excision repair in Escherichia coli involves formation of the UvrB-DNA complex and subsequent DNA incisions on either site of the damage by UvrC. In this paper, we studied the incision of substrates with different damages in varying sequence contexts. We show that there is not always a correlation between the incision efficiency and the stability(More)
We have isolated UvrB-DNA complexes by capture of biotinylated damaged DNA substrates on streptavidin-coated magnetic beads. With this method the UvrB-DNA preincision complex remains stable even in the absence of ATP. For the binding of UvrC to the UvrB-DNA complex no cofactor is needed. The subsequent induction of 3' incision does require ATP binding by(More)
Incision of damaged DNA templates by UvrBC in Escherichia coli depends on UvrA, which loads UvrB on the site of the damage. A 50-base pair 3' prenicked DNA substrate containing a cholesterol lesion is incised by UvrABC at two positions 5' to the lesion, the first incision at the eighth and the second at the 15th phosphodiester bond. Analysis of a 5'(More)
Operon fusion and S1 nuclease mapping have been employed to locate a putative uvrC promoter, which is situated approximately 200 bp ahead of the uvrC structural gene. The promoter sustains transcription towards the uvrC coding sequence and is inducible by DNA damaging agents. The inducibility is dependent on the Escherichia coli LexA and RecA functions.(More)
UvrB, the ultimate damage-recognizing component of bacterial nucleotide excision repair, contains a flexible beta-hairpin rich in hydrophobic residues. We describe the properties of UvrB mutants in which these residues have been mutated. The results show that Y101 and F108 in the tip of the hairpin are important for the strand-separating activity of UvrB,(More)