Identification of human DNA helicase V with the far upstream element-binding protein.
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Vindigni A, Ochem A, Triolo G, Falaschi A
Identification of human DNA helicase V with the far upstream element-binding protein.
Nucleic Acids Res. 2001 Mar 1;29(5):1061-7.
- PubMed ID
- 11222755 [ View in PubMed]
- Abstract
The properties of human DNA helicase V (HDH V) were studied in greater detail following an improved purification procedure. From 450 g of cultured cells, <0.1 mg of pure protein was isolated. HDH V unwinds DNA unidirectionally by moving in the 3' to 5' direction along the bound strand in an ATP- and Mg(2+)-dependent fashion. The enzyme is not processive and can also unwind partial RNA-RNA duplexes such as HDH IV and HDH VIII. The M:(r) determined by SDS-PAGE (66 kDa) corresponds to that measured under native conditions, suggesting that HDH V exists as a monomer in the nucleus. Microsequencing of the purified HDH V shows that this enzyme is identical to the far upstream element-binding protein (FBP), a protein that stimulates the activity of the c-myc gene by binding specifically to the 'FUSE' DNA region localized upstream of its promoter. The sequence of HDH V/FBP contains RGG motifs like HDH IV/nucleolin, HDH VIII/G3BP as well as other human RNA and DNA helicases identified by other laboratories.