FIG 1.

dsDUS supports the import of ssDNA. Gonococci (Ng005 ΔpilV) were incubated for 1 h with DNA fragments containing a single dye molecule at the 5′ end (top, stars). Subsequently, they were treated with DNase I. The fragments consisted of dsDNA (a), ssDNA (b), and ssDNA with a 16-base complementary oligonucleotide containing the DUS (c). (Top) Bright-field images; (bottom) fluorescence images. (d) Probability distribution of the total fluorescence intensity of individual cells incubated with dsDNA, ssDNA, or 100 bases of ssDNA with a 16-base complementary oligonucleotide containing the DUS. (e) Average fluorescence intensity of individual cells. Error bars, standard deviations from three independent experiments; gray bars, fragments with a sequence from λ phage DNA with a single Cy5 dye molecule at the 5′ end. Data are for >1,500 cells for each condition. arb. units, arbitrary units.