Hyper-T ATCase with novel (for wild-type apo holoenzyme) R167 conformation. Use F0-Fc maps!
Comments on a "new" ATCase Holoenzyme conformation termed the "Hyper-T" state. Conformational Plasticity of the Active Site Entrance in E. coli Aspartate Transcarbamoylase and Its Implication in Feedback Regulation
by Zhen Lei 1,Nan Wang 1,2,Hongwei Tan 1,Jimin Zheng 1,*
andZongchao Jia 3,*
The resultant Fo-Fc map reveals a problem near R167. The R167 conformation from 3CSU, first identified in our activated-state structure of the trimeric catalytic subunit of ATCase in 1998, is shown in purple. They should have realized that a hydrogen bond between a carbon of the threonine side chain and the tyrosine hydroxyl in the active site is beyond the energetic scope of "ground-state deformation". The PDB is rife with AI-related errors!
wild-type apo-form E. coli ATCase holoenzyme with an unusual open conformation of R167