Skip to main content
. 2003 Jun 15;31(12):3274–3286. doi: 10.1093/nar/gkg405

Figure 4.

Figure 4

pTP binds dsDNA and ssDNA with overlapping protein surfaces. DNA bound by 160 fmol pTP as a fraction of the total amount of DNA was used as the index (100%); the signals of pTP1 and pTP2 were summed. Error margins for individual points are less than 5% of binding. (A) Binding of 160 fmol pTP to TD(1–50) was challenged with increasing amounts of competitor DNA. Circular plasmid DNA (ds circ) was digested using AluI, Sau3A or CfoI to create blunt (ds blunt), 5′ overhang (ds 5′) or 3′ overhang (ds 3′) fragments. Single-stranded competitors were generated by heat denaturation followed by rapid cooling for 1 min to keep the single strands separated, after which pTP was immediately added. As a control on heat denaturation, single-stranded circular M13 DNA was used as a competitor. Controls for specific binding were unlabeled TD(1–50) probe and single-stranded T(1–50). (B) pTP binding to T(1–50) was challenged with increasing amounts of dsDNA and ssDNA competitors as described in (A).