Figure 3

DNA helicase assay. The recombinant Twinkle homologue purified from E. coli cells was tested for DNA helicase activity as described in the text. Lane 1 is the control substrate (S). Lane 2 is the heated control (HS), showing separation of the short labeled oligo from the substrate, which runs in this gel as a leading band with a diffuse smear; lane 3 (T+ATP), reaction using the purified recombinant protein with ATP; lane 4 (T-ATP), same reaction without ATP, lane 5 (C+ATP), control protein from E. coli cells lacking the expression construct with ATP, lane 6 (C–ATP), same reaction but without ATP.