Bzowska A, Luić M, Schröder W, Shugar D, Saenger W, Koellner G
Department of Biophysics, University Warsaw, Poland.
FEBS Lett. 1995 Jul 3;367(3):214-8. doi: 10.1016/0014-5793(95)00540-p.
Calf spleen purine nucleoside phosphorylase was purified to homogeneity and its amino acid sequence was determined. The complex of the enzyme with an N(7)-acycloguanosine inhibitor crystallized in the cubic space group P2(1)3, with unit cell dimension a = 94.02 A and one monomer in the asymmetric crystal unit. The biologically active trimer is formed by the crystallographic three-fold axis. The structure was solved by molecular replacement methods, using the model of the human erythrocyte enzyme, and refined at a resolution of 2.9 A to an R-factor of 0.21. The orientation of the inhibitor at the active site is examined in relation to the catalytic activity of the enzyme in the phosphorolysis of N(7)-beta-D-purine nucleosides.
