Reconstitution of repair-gap UV mutagenesis with purified proteins from Escherichia coli: a role for DNA polymerases III and II.
AUTOR(ES)
Tomer, G
RESUMO
Using a cell-free system for UV mutagenesis, we have previously demonstrated the existence of a mutagenic pathway associated with nucleotide-excision repair gaps. Here, we report that this pathway can be reconstituted by using six purified proteins: UvrA, UvrB, UvrC, DNA helicase II, DNA polymerase III core, and DNA ligase. This establishes the minimal requirements for repair-gap UV mutagenesis. DNA polymerase II could replace DNA polymerase III, although less effectively, whereas DNA polymerase I, the major repair polymerase, could not. DNA sequence analysis of mutations generated in the in vitro reaction revealed a spectrum typical of mutations targeted to UV lesions. These observations suggest that repair-gap UV mutagenesis is performed by DNA polymerase III, and to a lesser extent by DNA polymerase II, by filling-in of a rare class of excision gaps that contain UV lesions.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=39945Documentos Relacionados
- DNA Repair in Escherichia coli Mutants Deficient in DNA Polymerases I, II, and/or III
- A DNA-Unwinding Protein Isolated from Escherichia coli: Its Interaction with DNA and with DNA Polymerases
- DNA polymerase III of Escherichia coli is required for UV and ethyl methanesulfonate mutagenesis.
- Analysis of DNA Polymerases II and III in Mutants of Escherichia coli Thermosensitive for DNA Synthesis
- Porin channels in Escherichia coli: studies with liposomes reconstituted from purified proteins.