PMID: 24704254
Tresaugues L, Silvander C, Flodin S, Welin M, Nyman T, Graslund S, Hammarstrom M, Berglund H, Nordlund P
Structural Basis for Phosphoinositide Substrate Recognition, Catalysis, and Membrane Interactions in Human Inositol Polyphosphate 5-Phosphatases.
Structure. 2014 Apr 2. pii: S0969-2126(14)00073-2. doi:, 10.1016/j.str.2014.01.013.
SHIP2, OCRL, and INPP5B belong to inositol polyphosphate 5-phophatase subfamilies involved in insulin regulation and Lowes syndrome. The structural basis for membrane recognition, substrate specificity, and regulation of inositol polyphosphate 5-phophatases is still poorly understood. We determined the crystal structures of human SHIP2, OCRL, and INPP5B, the latter in complex with phosphoinositide substrate analogs, which revealed a membrane interaction patch likely to assist in sequestering substrates from the lipid bilayer. Residues recognizing the 1-phosphate of the substrates are highly conserved among human family members, suggesting similar substrate binding modes. However, 3- and 4-phosphate recognition varies and determines individual substrate specificity profiles. The high conservation of the environment of the scissile 5-phosphate suggests a common reaction geometry for all members of the human 5-phosphatase family.