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Phosphoglycerate kinase from the hyperthermophilic bacterium Thermotoga maritima
has been co-crystallized with its substrate 3-phosphoglycerate and the ATP
analogue AMP-PNP using the vapour diffusion method. Crystals were obtained from
a solution containing polyethylene glycol (MW 3000/8000) as precipitating agent.
A complete diffraction data set from orthorhombic crystals was collected up to
2.0 A resolution. The TmPGK crystallizes in the space group P2(1)2(1)2 (cell
dimensions: a = 62.0 A, b = 76.9 A, c = 87.5 A) with one molecule in the
asymmetric unit. The structure was solved by Patterson search methods using
Bacillus stearothermophilus PGK as a search model and was refined to a
crystallographic R factor of 22.0%. Compared to the enzyme from B.
stearothermophilus, horse, pig and yeast, the Thermotoga enzyme exhibits a
drastically reduced interdomain angle, similar to the one reported for PGK from
Trypanosoma brucei. Here we present crystallographic data of the first
high-resolution structure of a PGK in largely closed conformation, complexed
with the two products of the catalyzed reaction, and, at the same time, the
first PGK structure from a hyperthermophilic organism.
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