Zinc-dependent phospholipase C
Protein family
From Wikipedia, the free encyclopedia
In molecular biology, zinc-dependent phospholipases C is a family of bacterial phospholipases C enzymes, some of which are also known as alpha toxins.
| Zinc dependent phospholipase C | |||||||
|---|---|---|---|---|---|---|---|
Alpha toxin of Clostridium showing the zinc dependent phospholipase domain in red and the PLAT domain in yellow | |||||||
| Identifiers | |||||||
| Symbol | Zn_dep_PLPC | ||||||
| Pfam | PF00882 | ||||||
| InterPro | IPR001531 | ||||||
| PROSITE | PDOC00357 | ||||||
| SCOP2 | 1ah7 / SCOPe / SUPFAM | ||||||
| OPM superfamily | 81 | ||||||
| OPM protein | 1olp | ||||||
| CDD | cd11009 | ||||||
| |||||||
Bacillus cereus contains a monomeric phospholipase C EC 3.1.4.3 (PLC) of 245 amino-acid residues. Although PLC prefers to act on phosphatidylcholine, it also shows weak catalytic activity with sphingomyelin and phosphatidylinositol.[1] Sequence studies have shown the protein to be similar both to alpha toxin from Clostridium perfringens and Clostridium bifermentans, a phospholipase C involved in haemolysis and cell rupture,[2] and to lecithinase from Listeria monocytogenes, which aids cell-to-cell spread by breaking down the 2-membrane vacuoles that surround the bacterium during transfer.[3]
Each of these proteins is a zinc-dependent enzyme, binding 3 zinc ions per molecule.[4] The enzymes catalyse the conversion of phosphatidylcholine and water to 1,2-diacylglycerol and choline phosphate.[1][2][4]
In Bacillus cereus, there are nine residues known to be involved in binding the zinc ions: 5 His, 2 Asp, 1 Glu and 1 Trp. These residues are all conserved in the Clostridium alpha-toxin.
Some examples of this enzyme contain a C-terminal sequence extension that contains a PLAT domain which is thought to be involved in membrane localisation.[5][6]
