Table 1

AFM analysis of molecules from reactions containing a 660-bp DNA fragment alone or in the presence of DNA-PK components

DNA+Ku+DNA-PKDNA-PK + ATP
Looped2.3%17.3%16.5%11.2%
(7)(38)(43)(31)
Multi-DNA complex1.3%5.5%4.6%4.7%
(4)(12)(12)(13)
Linear96.4%77.3%78.8%84.1%
(292)(170)(205)(233)
n 303220260277
  • For statistical analysis, reactions were mounted unfixed and examined by AFM. The images were scored for the presence of linear, looped, or multiple DNA complexes. Reactions contained a 660-bp linear DNA fragment either alone (DNA), or in the presence of recombinant Ku (+Ku), recombinant Ku and DNA-PKcs (+DNA-PK), or recombinant Ku and DNA-PKcs plus ATP (DNA-PK + ATP). The percentage of reaction totals are followed by the number of molecules observed in parentheses.