[Chimera-users] force field for G-quadruplexes

Hello, recently I was looking into the capabilities of Chimera minimization tools to minimize the structure of a DNA G-quadruplex molecule. The problem is that all G-quadruplexes have an ion (K+ or Na+) in-between and stabilizing the tetrads. I wonder if the force field available in chimera are "decent" to water-minimize this kind of structures? ...and which one is more adapted, after all those are non-conventional DNA structures. Thanks in advance for your input Gilmar Salgado Université Segalen Laboratoire ARNA (INSERM U869) Institut Européen de Chimie et Biologie 2 rue Robert Escarpit 33 076 Pessac Cedex FRANCE +33(0) 540 0022 24 +33(0) 557 571 015 (fax)