Figure 1.

Identification of Z-DNA structure by cleavage with Za- and Zaa-Fok. (A) Schematic constructs of recombinant Za-Fok, Zaa-Fok, and Fok with a His tag and (Gly₄Ser)₃ linker. (B) pDHg16 contains CpG dinucleotide repeats. Arrows indicate ClaI and PstI cleavage sites. (C) The in vitro Z-DNA cleavage assay was analyzed on a 1% agarose gel. Linear and supercoiled pDHg16 was digested by various concentrations of Za-Fok, Zaa-Fok, or Fok. The molar ratio of Za-Fok, Zaa-Fok, or Fok to pDHg16 was 0, 2, 4, 6 and 8:1 (top and middle, lane 1-5, 7-11, bottom, lane 1-5, 8-12). Arrows indicate the resulting fragments produced by Za-Fok or Zaa-Fok, and PstI digestion (top and bottom, lane 1-5, 7-11). For a positive control, Zaa-Fok was used at the same time that Fok was tested (bottom, lane 6 and 13). Lane 6 (top and middle) and 7 (bottom) has DNA molecular mass markers. Lane 12 (top and middle) and 14 (bottom) has the restriction fragments of ClaI and PstI.