title: Crystallization and preliminary X-ray diffraction analysis of the 1,3-1,4-beta-D-glucanase from Fibrobacter succinogenes.
abstract: The truncated 1,3-1,4-beta-glucanase (1,3-1,4-beta-D-glucan 4-glucanohydrolase; E.C. 3.2.1.73) from Fibrobacter succinogenes was crystallized in four different forms by the vapour-diffusion method. Form A crystals have the largest trigonal P321 unit cell, diffracting to 3.0 A resolution with four to six molecules per asymmetric unit. Form B and C crystals belong to the same monoclinic space group P2(1), but the form B unit cell is twice as large as the unit cell of form C. Form B crystals diffract to 2.5 A resolution and contain four molecules per asymmetric unit. Form C crystals diffract to 2.1 A resolution and contain two molecules per asymmetric unit. Form D crystals have the smallest orthorhombic P2(1)2(1)2(1) unit cell, containing only one molecule per asymmetric unit, and diffract beyond 2.1 A resolution. The crystallization conditions for form B and C crystals are almost identical, except that form C crystals were grown in the presence of 2 mM Ca(2+) ions. It is likely that Ca(2+) directly binds to the glucanase, leading to unit-cell shrinkage as observed in other Bacillus glucanase crystals. A self-rotation search identified non-crystallographic twofold axes that combine with the crystallographic twofold dyads to give 222 symmetry for both form A and form B crystals, indicating that the glucanase has a tendency to pack in 222 symmetry.
authors.affiliation: Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan.
authors.forename: L C
authors.initials: LC
authors.lastname: Tsai
authors.forename: L F
authors.initials: LF
authors.lastname: Shyur
authors.forename: S S
authors.initials: SS
authors.lastname: Lin
authors.forename: H S
authors.initials: HS
authors.lastname: Yuan
mesh_terms: D001419:Bacteria / Q000201:enzymology*; D003460:Crystallization; D018360:Crystallography, X-Ray; D017353:Gene Deletion; D006026:Glycoside Hydrolases / Q000737:chemistry* / Q000235:genetics; D011487:Protein Conformation
chemical_list: D006026:Glycoside Hydrolases; C028020:licheninase