Biophysical Journal 90 1

Cover picture: Molecular dynamics simulations of DNA polymerase X (pol X) from the African swine fever virus suggest an induced-fit mechanism for its fidelity. (a) Comparison of the initial pol X structure in the ternary complex (protein/DNA/incoming correct nucleotide) in green, with the final structure obtained after 10.5 ns of simulation in blue. (b) Cartoon representation of the thumb subdomain of pol X before (green) and after (blue) the dynamics. Helix E in the thumb subdomain moves as much as 10 . (c) Comparison of pol X's helix E with the -helix N of x-ray crystal open and closed forms of mammalian DNA polymerase . See the article by Sampoli Ben tez et al. on page 42.