Novel DNA binding proteins highly specific to UV-damaged DNA sequences from embryos of Drosophila melanogaster.
Three new proteins which selectively bind to UV-damaged DNA were identified and purified to near homogeneity from UV-irradiated Drosophila melanogaster embryos through several column chromatographies. These proteins, tentatively designated as D-DDB P1, P2 and P3, can be identified as different complex bands in a gel shift assay by using UV-irradiated TC-31 probe DNA. Analysis of the purified D-DDB P1 fraction by native or SDS-polyacrylamide gel electrophoresis and FPLC-Superose 6 gel filtration demonstrated that it is a monomer protein which is a 30 kDa polypeptide. The D-DDB P2 protein is a monopolypeptide with a molecular mass of 14 kDa. Both D-DDB P1 and P2 highly prefer binding to UV-irradiated DNA, and have almost no affinity for non-irradiated DNA. Gel shift assays with either UV-irradiated DNA probes demonstrated that D-DDB P1 may show a preference for binding to (6-4) photoproducts, while D-DDB P2 may prefer binding to pyrimidine dimers. Both these proteins require magnesium ions for binding. D-DDB P1 is an ATP-preferent protein. These findings are discussed in relation to two recently described [Todo and Ryo (1991) Mutat. Res., 273, 85-93; Todo et al. (1993) Nature, 361, 371-374] DNA-binding factors from Drosophila cell extracts. A possible role for these DNA-binding proteins in lesion recognition and DNA-binding proteins in lesion recognition and DNA repair of UV-induced photo-products is discussed.
Kai
M
M
Department of Applied Biological Science, Faculty of Science and Technology, Science University of Tokyo, Chiba-ken, Japan.
Takahashi
T
T
Todo
T
T
Sakaguchi
K
K
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D004247:DNA / Q000378:metabolism* / Q000528:radiation effects*; D004249:DNA Damage; D004260:DNA Repair; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000196:embryology / Q000378:metabolism / Q000528:radiation effects; D008274:Magnesium / Q000378:metabolism; D008970:Molecular Weight; D011485:Protein Binding; D013696:Temperature; D014466:Ultraviolet Rays
D004268:DNA-Binding Proteins; D000255:Adenosine Triphosphate; D004247:DNA; D008274:Magnesium