(color online) Energetic features between the template DNA nucleotide and substrate NTPs. (a) Distributions of numbers of hydrogen bonds between the base of template DNA nucleotide (dC) and that of substrate GTP, dGTP, ATP, CTP, UTP are shown in black, red, blue, pink, and green, respectively. (b) Potential of mean force (PMF) along the distance between the base of template DNA nucleotide and that of substrate GTP and dGTP (NTP/base–dC10/base) are shown in black and red, respectively.