Fast protein shape retrieval with Laplacian Norm Alignement (LNA).

Introduction

Our method, called Laplacian Norm Alignment (LNA), characterizes proteins as a multi-dimensional sequence of quantity of deformation at different scales of the local space in which residues are embedded. More precisely, the discrete Laplace operator (discrete Laplacian) is used to measure the divergence of the gradient of residue positions in a graph that describes a protein weighted adjacency map. Laplacian coordinates of residues are resilient to translation and homothety but not to rotation. This limitation is overcome by only keeping for each residue the Euclidean norm of its Laplacian coordinates that is indeed invariant to rotation.
Dynamic programming algorithms (e.g. Needleman-Wunsch or Smith–Waterman) can then be used to match these multivariate descriptor sequences and achieve similar classification or clustering results compared to other approaches that requires in general more processing time. These algorithms require few memory and are implemented on Graphical Processing Unit (GPU) for an even faster computation time. This allows to compare one protein structure against 180,000 others within a second time span.


Please reference the LNA method and code in your paper as:

Nicolas Bonnel and Pierre-Francois Marteau, LNA: Fast Protein Classification Using A Laplacian Characterization of Tertiary Structure, IEEE/ACM Transaction on Computational Biology and Bioinformatics, in press PDF, homepage: http://www-irisa.univ-ubs.fr/LNA/


Downloads

The following archives contain LNA C/C++ sources for the one against one comparison (lnaOvO) and all against all comparison (lnaAvA) executables. cmake is required to compile theses sources.
A GPU implementation for all against all comparison is also provided. This implementation is written with Python and requires PyOpenCL.
Both AvA implementations require preprocessed databases, a python script is provided to build these preprocessed databases.
All files provided here are licenced under the GNU GPL v3.


Usage (Linux)


Region Bretagne Conseil Général du Morbihan European Regional Development Fund Ministere de l'Enseignement Superieur et de la Recherche IRISA Universite de Bretagne Sud Seaside team