Molecule of the Month: Phytase
Phytase is used in agriculture to mobilize indigestible phosphate compounds in livestock feed.
Phosphorus in Feed
Exploring the Structure
Phytase and Phytic Acid
The phytase AppA from Escherichia coli uses a histidine in its reaction (magenta), which is activated by a neighboring aspartate (pink). Phytic acid, because of its many phosphate groups (in red and orange), carries a strong negative charge, so it is recognized and positioned by an array of positively-charged arginine and lysine amino acids (in blue). To explore this structure in more detail, click on the image for an interactive JSmol.
Topics for Further Discussion
- Phytic acid is thought to play many other roles in cells, particularly because of its antioxidant properties. The Ligand page for inositol hexakisphosphate has links to structures of it bound to other proteins.
- Try searching for “inositol phosphate multikinase” at the RCSB PDB site to see a few of the enzymes that help build phytic acid.
Related PDB-101 Resources
- Browse Molecules and the Environment
- Browse Enzymes
- Browse Biotechnology
- Lei, X.G., Weaver, J.D., Mullaney, E., Ullah, A.H., Azain, M.J. (2013) Phytase, a new life for an “old” enzyme. Annual Review of Animal Bioscience 1: 283-309.
- 3mmj: Gruninger, R.J., Dobing, S., Smith, A.D., Bruder, L.M., Selinger, L.B., Wieden, H.J., Mosimann, S.C. (2012) Substrate binding in protein-tyrosine phosphatase-like inositol polyphosphatases. Journal of Biological Chemistry 287: 9722-9730.
- 3amr: Zeng, Y.F., Ko, T.P., Lai, H.L., Cheng, Y.S., Wu, T.H., Ma, Y., Chen, C.C., Yang, C.S., Cheng, K.J., Huang, C.H., Guo, R.T., Liu, J.R. (2011) Crystal structures of Bacillus alkaline phytase in complex with divalent metal ions and inositol hexasulfate Journal of Molecular Biology 409: 214-224.
- 1dkq: Lim, D., Golovan, S., Forsberg, C.W., Jia, Z. (2000) Crystal structures of Escherichia coli phytase and its complex with phytate. Nature Structural and Molecular Biology 7: 108-113.
- 4kbp: Klabunde, T., Strater, N., Frohlich, R., Witzel, H., Krebs, B. (1996) Mechanism of Fe(III)-Zn(II) purple acid phosphatase based on crystal structures. Journal of Molecular Biology 259: 737-748.
September 2018, David Goodsellhttp://doi.org/10.2210/rcsb_pdb/mom_2018_9