T. Gallagher et al., SUBTILISIN BPN' AT 1.6-ANGSTROM RESOLUTION - ANALYSIS FOR DISCRETE DISORDER AND COMPARISON OF CRYSTAL FORMS, Acta crystallographica. Section D, Biological crystallography, 52, 1996, pp. 1125-1135
Crystallography,"Biochemical Research Methods",Biology
The three-dimensional structure of the serine protease subtilisin BPN'
(SET) has been refined at 1.6 Angstrom resolution in space group C2 t
o a final R value of 0.17. 17 regions of discrete disorder have been i
dentified and analyzed. Two of these are dual-conformation peptide uni
ts; the remainder involve alternate rotamers of side chains either alo
ne or in small clusters. The structure is compared with previously rep
orted high-resolution models of SET in two other space groups, P2(1)2(
1)2(1) and P2(1). Apart from the surface, there are no significant var
iations in structure among the three crystal forms. Structural variati
ons observed at the protein surface occur predominantly in regions of
protein-protein contact. The crystal packing arrangements in the three
space groups are compared.