Subunit symmetry of tetrameric phosphorylase a.
K Bartels, PM Colman
Biophysics of Structure and Mechanism | Published : 1976
Native crystallographic data of tetrameric phosphorylase a crystals, space group P21, have been collected photographically to 3 A resolution. These data have been used in Patterson search methods in reciprocal and real space. The tetramers were found to exhibit molecular 222 symmetry. The cross vector between the centres of the two symmetry related tetramers in the unit cell was determined by two different translation function methods. On the basis of these rotation and translation function results a model for the arrangement of monomers within the tetramer and of tetramers in the unit cell is proposed; The 222 symmetry of the tetrameric molecule is found only when high resolution diffractio..View full abstract