Bacterial phosphatidylinositol-specific phospholipase C: structure, function, and interaction with lipids

The bacterial phosphatidylinositol-specific phospholipase C (PI-PLC) is a s mall, water-soluble enzyme that cleaves the natural membrane lipids PI, lys o-PI, and glycosyl-PI, The crystal structure, NMR and enzymatic mechanism o f bacterial PI-PLCs are reviewed. These enzymes consist of a single domain folded as a (beta alpha)(8)-barrel (TIM barrel), are calcium-independent, a nd interact weakly with membranes. Sequence similarity among PI-PLCs from d ifferent bacterial species is extensive, and includes the residues involved in catalysis. Bacterial PI-PLCs are structurally similar to the catalytic domain of mammalian PI-PLCs. Comparative studies of both prokaryotic and eu karyotic isozymes have proved useful for the identification of distinct reg ions of the proteins that are structurally and functionally important. (C) 1999 Published by Elsevier Science B.V. All rights reserved.