Figure 1.

(a) Crystal structure of the D. radiodurans RecQ catalytic core. The two RecA-like domains, D1 and D2, are colored in blue and red, respectively. The zinc-binding domain is highlighted in orange and the WH domain in green. ADP (magenta) is depicted in stick representation. (b) The size exclusion chromatography profile of DrRecQ. (c) The zinc-binding site of DrRecQ. The four conserved cysteine residues are shown in stick and a zinc ion is colored in magenta. The 2F_o-F_c electron density map contoured at the 2σ level is colored in gray.