Structural insights for fatty acid binding in a Lys49-phospholipase A(2): crystal structure of myotoxin II from Bothrops moojeni complexed with stearic acid
Watanabe, L., Soares, A.M., Ward, R.J., Fontes, M.R., Arni, R.K.(2005) Biochimie 87: 161-167
- PubMed: 15760708 
- DOI: https://doi.org/10.1016/j.biochi.2004.11.005
- Primary Citation of Related Structures:  
1XXS - PubMed Abstract: 
The crystal structure of dimeric Lys49-phospholipase A2 myotoxin-II from Bothrops moojeni (MjTX-II) co-crystallized with stearic acid (C(18)H(36)O(2)) has been determined at a resolution of 1.8 A. The electron density maps permitted the unambiguous inclusion of six stearic acid molecules in the refinement. Two stearic acid molecules could be located in the substrate-binding cleft of each monomer in positions, which favor the interaction of their carboxyl groups with active site residues. The way of binding of stearic acids to this Lys49-PLA(2)s is analogous to phospholipids and transition state analogues to catalytically active PLA(2)s. Two additional stearic acid molecules were located at the dimer interface region, defining a hitherto unidentified acyl-binding site on the protein surface. The strictly conserved Lys122 for Lys49-PLA(2)s may play a fundamental role for stabilization of legend-protein complex. The comparison of MjTX-II/satiric acid complex with other Lys-PLA(2)s structures whose putative fatty acids were located at their active site is also analysed. Molecular details of the stearic acid/protein interactions provide insights to binding in group I/II PLA(2)s, and to the possible interactions of Lys49-PLA(2)s with target membranes.
Organizational Affiliation: 
Departamento de Física, IBILCE, UNESP, S. J. do Rio Preto-SP, Brazil.