Abstract
We have purified to near homogeneity the major DNA-dependent ATPase from human cells. The pure enzyme has a mol. wt. of 68,000 and a minimum specific activity of approximately 150 U/mg. When the properties of the pure enzyme are compared with those of a less purified preparation, significant differences are observed both in structure and in function. These can be ascribed to the interaction of the ATPase with a DNA-binding protein (mol. wt. 28,000) that we can also purify to near homogeneity from the same cells and which is present in the less purified preparations of the ATPase. The ability of the less purified ATPase to stimulate DNA polymerase alpha in helicase fashion is probably due to the presence of the DNA-binding protein.
Full text
PDF
Images in this article
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Abdel-Monem M., Dürwald H., Hoffmann-Berling H. Enzymic unwinding of DNA. 2. Chain separation by an ATP-dependent DNA unwinding enzyme. Eur J Biochem. 1976 Jun 1;65(2):441–449. doi: 10.1111/j.1432-1033.1976.tb10359.x. [DOI] [PubMed] [Google Scholar]
- Banks G. R., Boezi J. A., Lehman I. R. A high molecular weight DNA polymerase from Drosophila melanogaster embryos. Purification, structure, and partial characterization. J Biol Chem. 1979 Oct 10;254(19):9886–9892. [PubMed] [Google Scholar]
- Carrara G., Gattoni S., Mercanti D., Tocchini-Valentini G. P. Purification of a DNA-binding protein from Xenopus laevis unfertilized eggs. Nucleic Acids Res. 1977 Aug;4(8):2855–2870. doi: 10.1093/nar/4.8.2855. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Cobianchi F., Biamonti G., Mastromei G., Falaschi A., Riva S. A DNA dependent ATPase from HeLa cells. Biochem Biophys Res Commun. 1982 Jan 29;104(2):402–409. doi: 10.1016/0006-291x(82)90651-9. [DOI] [PubMed] [Google Scholar]
- Cobianchi F., Riva S., Mastromei G., Spadari S., Pedrali-Noy G., Falaschi A. Enhancement of the rate of DNA polymerase-alpha activity on duplex DNA by a DNA-binding protein and a DNA-dependent ATPase of mammalian cells. Cold Spring Harb Symp Quant Biol. 1979;43(Pt 1):639–647. doi: 10.1101/sqb.1979.043.01.071. [DOI] [PubMed] [Google Scholar]
- De Jong P. J., Tommassen J. P., Van der Vliet P. C., Jansz H. S. Purification and characterization of DNA-dependent ATP phosphohydrolases from KB cells. Eur J Biochem. 1981 Jun;117(1):179–186. doi: 10.1111/j.1432-1033.1981.tb06318.x. [DOI] [PubMed] [Google Scholar]
- Laemmli U. K. Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature. 1970 Aug 15;227(5259):680–685. doi: 10.1038/227680a0. [DOI] [PubMed] [Google Scholar]
- Riva S., Clivio A., Valentini O., Cobianchi F. DNA binding proteins from calf thymus with an enhanced ability to stimulate DNA polymerase alpha in vitro. Biochem Biophys Res Commun. 1980 Oct 16;96(3):1053–1062. doi: 10.1016/0006-291x(80)90059-5. [DOI] [PubMed] [Google Scholar]
- Spadari S., Weissbach A. The interrelation between DNA synthesis and various DNA polymerase activities in synchronized HeLa cells. J Mol Biol. 1974 Jun 15;86(1):11–20. doi: 10.1016/s0022-2836(74)80003-3. [DOI] [PubMed] [Google Scholar]