Figure 3.

PfGBP2 binds to telomeric DNA and RNA sequences. (A) Recombinant 6x His-tagged PfGBP2 (full-length protein marked with arrow), expressed in E. coli and purified via nickel resin. Coomassie-blue-stained gel and western blot against the 6x His-tag. Images are representative of several independent preparations. (B) EMSA assays with the indicated oligonucleotides and bacterial extract containing PfGBP2 (‘+GBP2’), or equivalent extract containing no recombinant protein (‘-GBP2’) in the control condition. ‘Comp’, unlabeled competitor DNA of the same sequence. Images are representative of several independent experiments. (In all experiments, equal quantities of the A/T control oligo appeared less brightly: this was due to relatively inefficient biotinylation of the A/T oligo compared to the G-rich oligos.) (C) EMSA assay as in (B), using RNA instead of DNA. Competition was attempted with an excess of either unlabeled RNA or unlabeled DNA.