title: Insights into metal ion binding in phospholipases A2: ultra high-resolution crystal structures of an acidic phospholipase A2 in the Ca2+ free and bound states.
abstract: The electrophile Ca(2+) is an essential multifunctional co-factor in the phospholipase A(2) mediated hydrolysis of phospholipids. Crystal structures of an acidic phospholipase A(2) from the venom of Bothrops jararacussu have been determined both in the Ca(2+) free and bound states at 0.97 and 1.60 A resolutions, respectively. In the Ca(2+) bound state, the Ca(2+) ion is penta-coordinated by a distorted pyramidal cage of oxygen and nitrogen atoms that is significantly different to that observed in structures of other Group I/II phospholipases A(2). In the absence of Ca(2+), a water molecule occupies the position of the Ca(2+) ion and the side chain of Asp49 and the calcium-binding loop adopts a different conformation.
authors.affiliation: Department of Physics, IBILCE/UNESP, Cristovão Colombo 2265, São José do Rio Preto, SP 15054-000, Brazil.
authors.forename: M T
authors.initials: MT
authors.lastname: Murakami
authors.forename: A
authors.initials: A
authors.lastname: Gabdoulkhakov
authors.forename: N
authors.initials: N
authors.lastname: Genov
authors.forename: A C O
authors.initials: AC
authors.lastname: Cintra
authors.forename: C
authors.initials: C
authors.lastname: Betzel
authors.forename: R K
authors.initials: RK
authors.lastname: Arni
mesh_terms: D000818:Animals; D001665:Binding Sites; D017837:Bothrops / Q000378:metabolism; D002118:Calcium / Q000378:metabolism*; D003435:Crotalid Venoms / Q000201:enzymology; D003460:Crystallization; D018360:Crystallography, X-Ray / Q000379:methods; D054513:Group IV Phospholipases A2; D006860:Hydrogen Bonding; D008958:Models, Molecular; D010741:Phospholipases A / Q000737:chemistry* / Q000378:metabolism*; D054467:Phospholipases A2; D011485:Protein Binding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary
chemical_list: D003435:Crotalid Venoms; D010741:Phospholipases A; D054513:Group IV Phospholipases A2; D054467:Phospholipases A2; D002118:Calcium