ISSN:
1399-0047
Source:
Crystallography Journals Online : IUCR Backfile Archive 1948-2001
Topics:
Chemistry and Pharmacology
,
Geosciences
,
Physics
Notes:
The truncated 1,3-1,4-β-glucanase (1,3-1,4-β-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 Å resolution with four to six molecules per asymmetric unit. Form B and C crystals belong to the same monoclinic space group P21, but the form B unit cell is twice as large as the unit cell of form C. Form B crystals diffract to 2.5 Å resolution and contain four molecules per asymmetric unit. Form C crystals diffract to 2.1 Å resolution and contain two molecules per asymmetric unit. Form D crystals have the smallest orthorhombic P212121 unit cell, containing only one molecule per asymmetric unit, and diffract beyond 2.1 Å 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 Ca2+ ions. It is likely that Ca2+ 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.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1107/S0907444901010381
Permalink