1rlw

From Proteopedia

Revision as of 14:58, 5 November 2007

CALCIUM-PHOSPHOLIPID BINDING DOMAIN FROM CYTOSOLIC PHOSPHOLIPASE A2

Overview

Cytosolic phospholipase A2 (cPLA2) is a calcium-sensitive 85-kDa enzyme, that hydrolyzes arachidonic acid-containing membrane phospholipids to, initiate the biosynthesis of eicosanoids and platelet-activating factor, potent inflammatory mediators. The calcium-dependent activation of the, enzyme is mediated by an N-terminal C2 domain, which is responsible for, calcium-dependent translocation of the enzyme to membranes and that, enables the intact enzyme to hydrolyze membrane-resident substrates. The, 2.4-A x-ray crystal structure of this C2 domain was solved by multiple, isomorphous replacement and reveals a beta-sandwich with the same topology, as the C2 domain from phosphoinositide-specific phospholipase C delta 1., Two clusters of exposed hydrophobic residues surround two adjacent calcium, binding sites. This region, along with an adjoining strip of basic, residues, appear to constitute the membrane binding motif. The structure, provides a striking insight into the relative importance of hydrophobic, and electrostatic components of membrane binding for cPLA2. Although, hydrophobic interactions predominate for cPLA2, for other C2 domains such, as in "conventional" protein kinase C and synaptotagmins, electrostatic, forces prevail.

About this Structure

1RLW is a Single protein structure of sequence from Homo sapiens with CD and CA as ligands. Active as Phospholipase A(2), with EC number 3.1.1.4 Structure known Active Sites: CA1, CA2, CR1, CR2 and CR3. Full crystallographic information is available from OCA.

Reference

Crystal structure of a calcium-phospholipid binding domain from cytosolic phospholipase A2., Perisic O, Fong S, Lynch DE, Bycroft M, Williams RL, J Biol Chem. 1998 Jan 16;273(3):1596-604. PMID:9430701

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