Overview

This is a pionneering method for ab initio model analysis of solution scattering. It allows reconstruction the solution structure of a macromolecule from its SAXS profile. The method consists of fitting the scattering profile computed from sphere packet models of the molecule, using the Debye formula. The bead models are optimized by means of a genetic algorithm that searches the huge space of possible mass distributions and evolves convergent models.

DALAI_GA was originally developed as the result of a collaborative work by Dr. Pablo Chacón and Prof. Jose Manuel Andreu at the Centro de Investigaciones Biologicas, CSIC, Madrid. Prof. Federico Morán at the Department of Biophysics, UCM, Madrid Dr. Fernando Díaz, at the Department of Physical Biochemistry, Catholic University of Leuven(now at CIB) and Dr. Manolis Pantos at Daresbury Laboratory (DL), UK. This work  was also supported by much help from others. Special thanks for their help & suggestions are due to Prof. Paco Montero(UCM), Prof. Joan Bordas (UB) and Dr.G. Grossmann (DL).

The currently available program DALAI_GA version 3 (2006), an improved genetic algorithm which has been employed to reconstruct the solution structure from a dozen protein profiles so far. We encourage further applications of the method.

References:

P. Chacón, F. Morán, J. F. Díaz, E. Pantos, and J. M. Andreu Low-Resolution structures of Proteins in Solution Retrieved from X-Ray Scattering with a Genetic Algorithm, Biophys. J. 1998 74: 2760-2775.

Chacón, P., Díaz, J.F., Morán, F. y Andreu, J.M. Reconstruction of protein form with X-ray solution scattering and a genetic algorithm J. Mol. Biol. 2000 299: 1289-1302.