Specificity determinants in phosphoinositide dephosphorylation: crystal structure of an archetypal inositol polyphosphate 5-phosphatase.

Abstract

Inositol polyphosphate 5-phosphatases are central to intracellular processes ranging from membrane trafficking to Ca(2+) signaling, and defects in this activity result in the human disease Lowe syndrome. The 1.8 resolution structure of the inositol polyphosphate 5-phosphatase domain of SPsynaptojanin bound to Ca(2+) and inositol (1,4)-bisphosphate reveals a fold and an active site His and Asp pair resembling those of several Mg(2+)-dependent nucleases. Additional loops mediate specific inositol polyphosphate contacts. The 4-phosphate of inositol (1,4)-bisphosphate is misoriented by 4.6 compared to the reactive geometry observed in the apurinic/apyrimidinic endonuclease 1, explaining the dephosphorylation site selectivity of the 5-phosphatases. Based on the structure, a series of mutants are described that exhibit altered substrate specificity providing general determinants for substrate recognition.

• Authors: Y Tsujishita, S Guo, L E Stolz, J D York, J H Hurley
• Journal: Cell (Cell) Vol. 105 Issue 3 Pg. 379-89 (May 04 2001) ISSN: 0092-8674 [Print] United States
• PMID: 11348594 (Publication Type: Journal Article)

Chemical References

• Enzyme Inhibitors
• Inositol Phosphates
• Nerve Tissue Proteins
• Recombinant Proteins
• inositol 1,4-bis(phosphate)
• synaptojanin
• Phosphoric Monoester Hydrolases
• Inositol Polyphosphate 5-Phosphatases
• Calcium

Topics

• Amino Acid Sequence
• Binding Sites
• Calcium (metabolism)
• Catalytic Domain
• Cloning, Molecular
• Crystallography, X-Ray
• Enzyme Inhibitors (metabolism)
• Humans
• Inositol Phosphates (metabolism)
• Inositol Polyphosphate 5-Phosphatases
• Models, Molecular
• Molecular Sequence Data
• Mutation
• Nerve Tissue Proteins (chemistry, genetics, metabolism)
• Phosphoric Monoester Hydrolases (chemistry, genetics, metabolism)
• Phosphorylation
• Protein Conformation
• Protein Folding
• Protein Structure, Quaternary
• Protein Structure, Secondary
• Protein Structure, Tertiary
• Recombinant Proteins (chemistry, genetics, metabolism)
• Schizosaccharomyces (enzymology, genetics)
• Sequence Alignment
• Substrate Specificity