This is what we call N/Q/H flips done as part of phenix.refine refinement based on Molprobity evaluation. Pavel
On Wed, May 20, 2015 at 2:10 PM, Smith Liu <smith_liu...@163.com> wrote: > Dear All, > > Suppose the protein crystal resolution is about 2-3A, then in the map it > should be rather difficult to distinguish the C and N in the sidechain of > HIS. In this way we may regard the sidechain of HIS is flippable. But > suppose in one flipped conformation of the HIS, the free N in the sidechain > of HIS can form H-bond with the neighbour H of the OH of the Thr, in the > other flipped conformation of the HIS, the free N in the sidechain of HIS > cannot form H-bond with the neighbour H of the OH of the Thr (caused by > distance issue). > > Suppose whether the H-bond forms between the free N in the sidechain of > HIS and the neighbour H of the OH of the Thr was very important > biologically, in this situation how can we distinguish whether the H-bond > forms? > > Smith > > >