|
type |
Journal Article |
authors |
Rao, G. S.; Mottonen, J.; Goldsmith, E. J.; Cook, P. F. |
title |
Crystallization and preliminary X-ray data for the A-isozyme of O- acetylserine sulfhydrylase from Salmonella typhimurium |
journal |
J Mol Biol |
Activity |
2.5.1.47 |
ui |
93294864 |
year |
(1993) |
volume |
231 |
number |
4 |
pages |
1130-2. |
| |
keywords |
Crystallization |
abstract |
The A-isozyme of O-acetylserine sulfhydrylase, a pyridoxal phosphate- dependent enzyme isolated from Salmonella typhimurium catalyzes the synthesis of L-cysteine from O-acetyl-L-serine and sulfide. The pyridoxal form of the enzyme has been crystallized in two different forms. One form is in the orthorhombic space group P2(1)2(1)2(1) with cell constants a = 144.4 A, b = 96.9 A and c = 54.3 A and contains two monomers each of molecular weight 34,000 per asymmetric unit. The second form is in a hexagonal space group with unit cell dimensions a = b = 115 A, and c = 348 A and contains two 68,000 dimers per asymmetric unit. Complete native enzyme data sets have been collected for both crystal forms using an R-Axis II detector. A search for suitable heavy- atom derivatives is underway. Although both crystal forms diffract X- rays to better than 2.5 A, the orthorhombic form is more suited to a detailed structural analysis due to the extended lifetime in the X-ray beam and the relative size of the unit cell. |
last changed |
2003/03/17 14:53 |
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