Enhancement of the uvrA gene dosage reduces pyrimidine dimer excision in UV-irradiated Escherichia coli.
E. coli possesses an efficient repair mechanism able to remove pyrimidine dimers from UV-irradiated DNA, which is catalyzed by UvrABC endonuclease. In E. coli B/r Hcr+ cells transformed with a multicopy plasmid harboring a gene coding for UvrA, the excision capacity was greatly reduced. The course of thymine dimer excision was investigated using the enzymatic as well as the radiochromatographic method and the results are discussed in term of nonspecific interaction between the excess of UvrA protein and undamaged DNA duplex.
Betina
S
S
Department of Microbiology, Faculty of Chemistry, Slovak Technical University, Bratislava.
Masek
F
F
Kleibl
K
K
D004260:DNA Repair; D004591:Electrophoresis, Polyacrylamide Gel; D004706:Endodeoxyribonucleases / Q000235:genetics*; D004790:Enzyme Induction; D004926:Escherichia coli / Q000235:genetics* / Q000528:radiation effects*; D029968:Escherichia coli Proteins; D005784:Gene Amplification; D005798:Genes, Bacterial / Q000235:genetics; D010957:Plasmids; D011740:Pyrimidine Dimers; D014466:Ultraviolet Rays
D029968:Escherichia coli Proteins; D011740:Pyrimidine Dimers; D004706:Endodeoxyribonucleases; C036385:endodeoxyribonuclease uvrABC