Top: in MD simulations of the ADP.P i state, R359 and F360 undergo a correlated motion on a microsecond timescale, evidenced by fluctuations of the side-chain dihedral angle (F360 1 ) and the phosphatearginine binding geometry, represented by the distances d1 and d2 between R359-N1/N2 and the cleaved P i ion. Residual densities at the D1 active site after assignment of the protein and ADP. A transition between the two stable geometries, states A and B, occurs here after ~1,200 ns. Bottom: the side-chain rotamers are visible in the experimental cryo-EM density.
