Structural basis of BS Figure 2 Fig. 3. The trace of the PcrA helicase from residues 4 to 652 and the structural model of the BLM protein from residues 655 to 1029 are shown. Electrostatic surface of the model with the same view as left.
Negative potential is shown in red, positive potential in blue.
The surface potential is negative over most of the surface except for the DNA-binding cleft. The seven conserved helicase motifs, I, Ia, II, III, IV, V, and VI, are shown in blue, light blue, orange, magenta, red, white, and green, respectively. The docked ATP is displayed in green. The residues of BS-causing mutations are displayed with sidechains in green and residue K695 corresponding to mutation K703A on mouse BLM is also displayed.