Abstract
An ATP-dependent DNAase has been purified to homogeneity from extracts of Alcaligenes faecalis, and has been shown to couple the degradation of DNA to the hydrolysis of ATP. Enzyme activity also requires divalent ions, with Mn2+, Mg2+ and Co2+ being effective cofactors for both DNAase and ATPase activities. We have studied the intermediates formed by the enzyme during the degradation of duplex DNA with each of these cofactors using sedimentation velocity, binding to nitrocellulose filters and sensitivity to a nuclease specific for single-stranded DNA. With Mn2+ or Co2+, the enzyme acts processively to produce mostly acid-soluble material and acid-insoluble single-strand fragments up to 400-nucleotides long. However, with Mg2+ present, the enzyme produces intermediates comprising a duplex region with one or more single-strand tails, while little acid-soluble oligonucleotide is formed. From these results, we propose a model to describe the mechanism by which the ATP-dependent DNAase from A. faecalis degrades duplex DNA.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.