Topoisomerase Iactivity associated withhuman immunodeficiency virus (HIV) particles andequine infectious anemiavirus core

the marginal effectofATP,couldnotbeattributed to anoverdoseoftheextractsthatwemightuseintheseparticularexperiments, sincetheywereobserved in repeatedexperiments with upto 100-folddilutions ofthese extracts. Thesedifferences suggestthat theviral andthe hostcell topoI activities reflected twodistinctforms of this enzyme.