ISSN:
1399-0047
Source:
Crystallography Journals Online : IUCR Backfile Archive 1948-2001
Topics:
Chemistry and Pharmacology
,
Geosciences
,
Physics
Notes:
Xylose isomerases from Thermotoga neapolitana (TNXI) and Thermoanaerobacterium thermosulfurigenes (TTXI) share 70.4% sequence identity and are thermostable. The double mutants Trp138Phe/Val185Thr of TNXI and TTXI have higher catalytic efficiencies than TNXI and TTXI, respectively. The Trp138Phe/Val185Thr TNXI and TTXI mutants were overexpressed in Escherichia coli strain BL21(DE3) and purified. Crystals of the two proteins were grown with polyethylene glycol 8000 as the major precipitant by the hanging-drop vapour-diffusion method. Crystals of the TNXI mutant were obtained in the absence of substrate, in complex with glucose and in complex with fructose. Crystals of the TTXI mutant were obtained complexed with glucose. Diffraction data were collected at 1.9, 2.1 and 2.1 Å resolution for the fructose–TNXI mutant, glucose–TNXI mutant and substrate-unbound TNXI mutant, respectively. The diffraction data for the glucose–TTXI mutant were collected at 2.0 Å resolution. The crystals belong to the orthorhombic space groups C2221 (TNXI mutant) and P212121 (TTXI mutant). The TNXI and TTXI mutant crystals contain two and four monomers in the asymmetric unit, respectively.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1107/S0907444901012835
Permalink