Title
Can molecular dynamics simulations help in discriminating correct from erroneous protein 3D models?
Abstract
Recent approaches for predicting the three-dimensional (3D) structure of proteins such as de novo or fold recognition methods mostly rely on simplified energy potential functions and a reduced representation of the polypeptide chain. These simplifications facilitate the exploration of the protein conformational space but do not permit to capture entirely the subtle relationship that exists between the amino acid sequence and its native structure. It has been proposed that physics-based energy functions together with techniques for sampling the conformational space, e.g., Monte Carlo or molecular dynamics (MD) simulations, are better suited to the task of modelling proteins at higher resolutions than those of models obtained with the former type of methods. In this study we monitor different protein structural properties along MD trajectories to discriminate correct from erroneous models. These models are based on the sequence-structure alignments provided by our fold recognition method, FROST. We define correct models as being built from alignments of sequences with structures similar to their native structures and erroneous models from alignments of sequences with structures unrelated to their native structures.For three test sequences whose native structures belong to the all-alpha, all-beta and alphabeta classes we built a set of models intended to cover the whole spectrum: from a perfect model, i.e., the native structure, to a very poor model, i.e., a random alignment of the test sequence with a structure belonging to another structural class, including several intermediate models based on fold recognition alignments. We submitted these models to 11 ns of MD simulations at three different temperatures. We monitored along the corresponding trajectories the mean of the Root-Mean-Square deviations (RMSd) with respect to the initial conformation, the RMSd fluctuations, the number of conformation clusters, the evolution of secondary structures and the surface area of residues. None of these criteria alone is 100% efficient in discriminating correct from erroneous models. The mean RMSd, RMSd fluctuations, secondary structure and clustering of conformations show some false positives whereas the residue surface area criterion shows false negatives. However if we consider these criteria in combination it is straightforward to discriminate the two types of models.The ability of discriminating correct from erroneous models allows us to improve the specificity and sensitivity of our fold recognition method for a number of ambiguous cases.
Year
DOI
Venue
2008
10.1186/1471-2105-9-6
BMC Bioinformatics
Keywords
Field
DocType
structure alignment,false positive,fold recognition,protein binding,algorithms,binding sites,structural similarity,molecular dynamic,three dimensional,protein folding,surface area,bioinformatics,sequence alignment,spectrum,monte carlo,protein conformation,root mean square deviation,microarrays,kinetics,amino acid sequence,proteins,protein structure,secondary structure,computer simulation
Sequence alignment,Monte Carlo method,Protein folding,Force field (chemistry),Computer science,Threading (protein sequence),Molecular dynamics,Bioinformatics,Protein structure
Journal
Volume
Issue
ISSN
9
1
1471-2105
Citations 
PageRank 
References 
28
0.57
4
Authors
3
Name
Order
Citations
PageRank
Jean-François Taly1763.05
Antoine Marin2280.57
Jean-françois Gibrat31266.08