Figure 1.
Experimental ESP map EMD-8361. (a) The ESP map with computational sharpening using ΔB = −58.5 Å2. (b) No sharpening, ΔB = 0Å. (c) Blurring, ΔB = +30 Å2. (d) Blurring, ΔB = +50 Å2. Maps are contoured at +2.5σ (left), +5.0σ (middle) and +7.5σ (right) for the Mg2+ site in question, known as the Mg-J1 site. Arrows highlight some notable features. Magenta arrows show that the volume for Mg2+ dramatically increases with increasing ΔB values, i.e. particularly at +5.0σ contouring level, whereas the volume for nucleobases remains unchanged, i.e. green arrows for N1 and N3 of G1031, and cyan arrows for C2 of A1060. Blue arrows indicate that the ESP value remains the highest on-atom ESP value on C1′ among all C atoms as well as among all the N and O atoms of the two nucleotides.