Journal
JOURNAL OF BIOLOGICAL CHEMISTRY
Volume 280, Issue 27, Pages 25450-25460Publisher
AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC
DOI: 10.1074/jbc.M501995200
Keywords
-
Categories
Ask authors/readers for more resources
We have investigated the DNA substrate specificity of BACH1 ( BRCA1- associated C- terminal helicase). The importance of various DNA structural elements for efficient unwinding by purified recombinant BACH1 helicase was examined. The results indicated that BACH1 preferentially binds and unwinds a forked duplex substrate compared with a duplex flanked by only one single-stranded DNA ( ssDNA) tail. In support of its DNA substrate preference, helicase sequestration studies revealed that BACH1 can be preferentially trapped by forked duplex molecules. BACH1 helicase requires a minimal 5' ssDNA tail of 15 nucleotides for unwinding of conventional duplex DNA substrates; however, the enzyme is able to catalytically release the third strand of the homologous recombination intermediate D- loop structure irrespective of DNA tail status. In contrast, BACH1 completely fails to unwind a synthetic Holliday junction structure. Moreover, BACH1 requires nucleic acid continuity in the 5 ' ssDNA tail of the forked duplex substrate within six nucleotides of the ssDNA- dsDNA junction to initiate efficiently DNA unwinding. These studies provide the first detailed information on the DNA substrate specificity of BACH1 helicase and provide insight to the types of DNA structures the enzyme is likely to act upon to perform its functions in DNA repair or recombination.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available