Download MendeleyStructures of Selenomonas ruminantium Phytase in Complex with Persulfated Phytate; DSP Phytase Fold and Mechanism for Sequential Substrate Hydrolysis
Chu, H.M., Guo, R.T., Lin, T.W., Chou, C.C., Shr, H.L., Lai, H.L., Tang, T.Y., Cheng, K.J., Selinger, B.L., Wang, A.H.-J.(2004) Structure 12: 2015-2024
- PubMed: 15530366
- DOI: https://doi.org/10.1016/j.str.2004.08.010
- Primary Citation of Related Structures:
1U24, 1U25, 1U26 - PubMed Abstract:
Various inositide phosphatases participate in the regulation of inositol polyphosphate signaling molecules. Plant phytases are phosphatases that hydrolyze phytate to less-phosphorylated myo-inositol derivatives and phosphate. The phytase from Selenomonas ruminantium shares no sequence homology with other microbial phytases. Its crystal structure revealed a phytase fold of the dual-specificity phosphatase type. The active site is located near a conserved cysteine-containing (Cys241) P loop. We also solved two other crystal forms in which an inhibitor, myo-inositol hexasulfate, is cocrystallized with the enzyme. In the "standby" and the "inhibited" crystal forms, the inhibitor is bound, respectively, in a pocket slightly away from Cys241 and at the substrate binding site where the phosphate group to be hydrolyzed is held close to the -SH group of Cys241. Our structural and mutagenesis studies allow us to visualize the way in which the P loop-containing phytase attracts and hydrolyzes the substrate (phytate) sequentially.
Organizational Affiliation:
Institute of Biochemical Sciences, National Taiwan University, Taipei 106, Taiwan.
