Structure of an N-terminally truncated selenophosphate synthetase from Aquifex aeolicus
Matsumoto, E., Sekine, S., Akasaka, R., Otta, Y., Katsura, K., Inoue, M., Kaminishi, T., Terada, T., Shirouzu, M., Yokoyama, S.(2008) Acta Crystallogr Sect F Struct Biol Cryst Commun 64: 453-458
- PubMed: 18540050 
- DOI: https://doi.org/10.1107/S1744309108012074
- Primary Citation of Related Structures:  
2ZAU - PubMed Abstract: 
Selenophosphate synthetase (SPS) catalyzes the activation of selenide with ATP to synthesize selenophosphate, the reactive selenium donor for biosyntheses of both the 21st amino acid selenocysteine and 2-selenouridine nucleotides in tRNA anticodons. The crystal structure of an N-terminally (25 residues) truncated fragment of SPS (SPS-DeltaN) from Aquifex aeolicus has been determined at 2.0 A resolution. The structure revealed SPS to be a two-domain alpha/beta protein, with domain folds that are homologous to those of PurM-superfamily proteins. In the crystal, six monomers of SPS-DeltaN form a hexamer of 204 kDa, whereas the molecular weight estimated by ultracentrifugation was approximately 63 kDa, which is comparable to the calculated weight of the dimer (68 kDa).
Organizational Affiliation: 
Systems and Structural Biology Center, RIKEN Yokohama Institute, 1-7-22 Suehiro-cho, Tsurumi, Yokohama 230-0045, Japan.