High-resolution structure of phenol hydroxylase and correction of sequence errors.

The crystal structure model of phenol hydroxylase has been corrected for 11 sequence errors and refined against new data to 1.7 A resolution. The higher resolution data together with careful exploitation of non-crystallographic symmetry restraints and the use of many small groups for refinement of anisotropic displacement parameters resulted in a large decrease in the crystallographic R factor. The final crystallographic free R factor is 18.0%, which should be compared with the values of 27.8% for the previously published model (PDB code 1foh). The rebuilding and re-refinement procedure is described. A comparison with the previously published model was performed and possible biochemical implications are discussed. No large differences suggesting gross errors in the earlier model were found. The actual differences between these two models give an indication of the level of ambiguity and inaccuracy that may be found in a well refined protein model at 2.4 A resolution.