Reaction: Couples ATP hydrolysis with the unwinding of duplex DNA by translocating in the 3'-5' direction.
Other name(s): uvrD (gene name); rep (gene name); RECQ (gene name); MER3 (gene name); Holliday junction DNA helicase
Systematic name: DNA 3'-5' helicase (ATP-hydrolysing)
Comments: Helicases are motor proteins that can transiently catalyse the unwinding of energetically stable duplex DNA or RNA molecules by using ATP hydrolysis as the source of energy (although other nucleoside triphosphates can replace ATP in some cases). DNA helicases unwind duplex DNA and are involved in replication, repair, recombination, transcription, pre-rRNA processing, and translation initiation. Mechanistically, DNA helicases are divided into those that can translocate in the 3'-5' direction and those that translocate in the 5'-3' direction with respect to the strand on which they initially bind. This entry describes a number of DNA helicases that translocate in the 3'-5' direction. Many of the enzymes require a 3' single-stranded DNA tail. The Rep protein is a component of the bacterial replisome, providing a replication fork-specific motor. The UvrD enzyme, found in Gram-negative bacteria, is involved in maintenance of chromosomal integrity. The RecQ proteins are a family of eukaryotic helicases that are involved in DNA replication, transcription and repair. The Mer3 helicase, found in fungi and plants, is required for crossover formation during meiosis. cf. EC 5.6.2.3, DNA 5'-3' helicase.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Takahashi, S., Hours, C., Chu, A. and Denhardt, D.T. The rep mutation. VI. Purification and properties of the Escherichia coli rep protein, DNA helicase III. Can. J. Biochem. 57 (1979) 855-866. [PMID: 383240]
2. Nakagawa, T., Flores-Rozas, H. and Kolodner, R.D. The MER3 helicase involved in meiotic crossing over is stimulated by single-stranded DNA-binding proteins and unwinds DNA in the 3' to 5' direction. J. Biol. Chem. 276 (2001) 31487-31493. [PMID: 11376001]
3. Ozsoy, A.Z., Sekelsky, J.J. and Matson, S.W. Biochemical characterization of the small isoform of Drosophila melanogaster RECQ5 helicase. Nucleic Acids Res. 29 (2001) 2986-2993. [PMID: 11452023]
4. Curti, E., Smerdon, S.J. and Davis, E.O. Characterization of the helicase activity and substrate specificity of Mycobacterium tuberculosis UvrD. J. Bacteriol. 189 (2007) 1542-1555. [PMID: 17158674]