Figure 3.

Schematic, sequence alignment and structural/functional comparison of ARTD1 and ARTD2. (A) Domain organization of DNA dependent ARTDs. (B) Protein sequence alignment of ARTD1_WGR, ARTD2_WGR and ARTD3_WGR. Identical residues are highlighted in red and similar residues in yellow. (C) Structural representation of ARTD2_WGR bound to DNA break with 5′-phosphate (blue). The catalytic domain (CAT) (PDB ID 4PJV) was positioned based on ARTD1 structure seen in panel D. (D) Structural representation of ARTD1 bound to DNA break (purple) (PDB ID 4DQY). WGR, C-terminal catalytic domain (CAT) and Zinc finger (Zn1) are labelled. The superimposed model of ARTD1 and ARTD2 is shown in Supplementary Figure S11. (E) The specific DNA dependent activity of ARTD2_FL, ARTD2_WGR+CAT, ARTD1_FL, ARTD1_WGR+CAT were measured using fluorescence activity assay as described in the materials and methods. ARTD2_FL at 50 nM was incubated for 1 h, ARTD2_WGR+CAT and ARTD1_WGR+CAT at 50 nM were incubated for 2 h, and ARTD1_FL at 25 nM was incubated for 2 h. The NAD⁺ concentration in all the experiments was 5 μM. Data are presented as means and standard deviation of the quadruplicates. (F) The interaction of ARTD2_WGR+CAT and ARTD1_WGR+CAT with DNA were studied using EMSA.