Low-resolution structural characterization of the arginine repressor/activator from Bacillus subtilis: a combined X-ray crystallographic and electron microscopical approach.
نویسندگان
چکیده
Attempts to determine the X-ray crystal structure of the intact homohexameric arginine repressor/activator from B. subtilis have so far been unsuccessful. The major problem appears to be the lack of an isomorphous heavy-atom derivative with a manageable number of substitution sites. Here it is shown how electron microscopy of thin three-dimensional crystals, the same as those used for the X-ray crystallographic studies, made it possible (i) to obtain experimental support for some conclusions drawn on the basis of X-ray data alone, (ii) to determine the low-resolution distribution of electron density in several different crystallographic projections, and (iii) to obtain a tentative low-resolution model of the whole hexamer.
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عنوان ژورنال:
- Acta crystallographica. Section D, Biological crystallography
دوره 54 Pt 2 شماره
صفحات -
تاریخ انتشار 1998