ISSN:
1399-0047
Source:
Crystallography Journals Online : IUCR Backfile Archive 1948-2001
Topics:
Chemistry and Pharmacology
,
Geosciences
,
Physics
Notes:
The etiologic agent of tuberculosis, Mycobacterium tuberculosis, has been shown to secrete the enzyme glutamine synthetase (TB-GS) which is apparently essential for infection. Four crystal forms of a recombinant TB-GS were grown. The one chosen for synchrotron X-ray data collection belongs to space group P212121 with unit-cell dimensions 208 × 258 × 274 Å, yielding 2.4 Å resolution data. A Matthews number of 2.89 Å3 Da−1 is found, corresponding to 24 subunits of molecular mass 1300 kDa in the asymmetric unit. From earlier work, the structure of Salmonella typhimurium GS, which is 51% identical in sequence to TB-GS, is known to be dodecameric with 622 symmetry. Self-rotation calculations on the TB-GS X-ray data reveal only one set of sixfold and twofold axes of symmetry. A Patterson map calculated from the native X-ray data confirms that there are two dodecamers in the asymmetric unit, having both their sixfold and twofold axes parallel to one another.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1107/S0907444998017685
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