Fig. 1

Structures of dUTPases. A Multiple amino acid sequence alignment of dUTPases. Sequences were presented with the similarity symbols, matches (*), highly similar (:), and medium similarity (.). The conserved motifs, M1–M5, were highlighted cyan. Sequences in α-helix in M2 involved in the initial grasp of substrate-water complex were highlighted magenta [19]. In D. ryukyuensis dUTPase, an intentional mutation in the expression construct, Arg66Lys, to avoid thrombin cleavage was shown in yellow (Additional file 1: Fig. S1), and potential compensatory substitutions against H. sapiens dUTPase, Phe29 and Tyr139, were indicated by underline. In H. sapiens dUTPase, reported nuclear localization signal [29] was highlighted gray, and residues involved in uracil recognition in the conserved motif [9] were indicated by underlines. In dUTPases from D. ryukyuensis, H. sapiens and P. falciparum, missing amino acid residues in the 3D-structure models were marked by doted underlines, and two neighboring residues were marked green as visual markers (B). B 3D structure of dUTPase. a A trimer view of Hs-dUTPase in the cartoon view (PDB code, 3ehw) with only the residues involved in the active site centered the α–helix of A chain were shown in sticks (magenta enclosing). b A schematic diagram of substrate, an inhibitor dUMPNPP (2′-deoxyuridine-5′-[(α,β)-imido]triphosphate), and active site residues from the enclosing in A. c A monomer view of Hs-dUTPase. d A monomer view of Dr-dUTPase model. e A monomer view of Pf-dUTPase (1vyq). In c-e, color coding matched with A