Results 1  10
of
61
TMalign: A protein structure alignment algorithm based on TMscore
 Nucleic Acids Research
"... TMscore ..."
Matt: local flexibility aids protein multiple structure alignment
 PLoS Comput. Biol
, 2008
"... Even when there is agreement on what measure a protein multiple structure alignment should be optimizing, finding the optimal alignment is computationally prohibitive. One approach used by many previous methods is aligned fragment pair chaining, where short structural fragments from all the proteins ..."
Abstract

Cited by 15 (1 self)
 Add to MetaCart
Even when there is agreement on what measure a protein multiple structure alignment should be optimizing, finding the optimal alignment is computationally prohibitive. One approach used by many previous methods is aligned fragment pair chaining, where short structural fragments from all the proteins are aligned against each other optimally, and the final alignment chains these together in geometrically consistent ways. Ye and Godzik have recently suggested that adding geometric flexibility may help better model protein structures in a variety of contexts. We introduce the program Matt (Multiple Alignment with Translations and Twists), an aligned fragment pair chaining algorithm that, in intermediate steps, allows local flexibility between fragments: small translations and rotations are temporarily allowed to bring sets of aligned fragments closer, even if they are physically impossible under rigid body transformations. After a dynamic programming assembly guided by these ‘‘bent’ ’ alignments, geometric consistency is restored in the final step before the alignment is output. Matt is tested against other recent multiple protein structure alignment programs on the popular Homstrad and SABmark benchmark datasets. Matt’s global performance is competitive with the other programs on Homstrad, but outperforms the other programs on SABmark, a benchmark of multiple structure alignments of proteins with more distant homology. On both datasets, Matt demonstrates an ability to better align the ends of ahelices and bstrands, an important characteristic of any structure alignment program intended to help construct a structural template library for threading approaches to the inverse proteinfolding
TOPOFITDB, a database of protein structural alignments based on the TOPOFIT method
 Nucleic Acids Res
, 2007
"... TOPOFITDB (TDB) is a public webbased database of protein structural alignments based on the TOPOFIT method, providing a comprehensive resource for comparative analysis of protein structure families. The TOPOFIT method is based on the discovery of a saturation point on the alignment curve (topomax ..."
Abstract

Cited by 7 (2 self)
 Add to MetaCart
TOPOFITDB (TDB) is a public webbased database of protein structural alignments based on the TOPOFIT method, providing a comprehensive resource for comparative analysis of protein structure families. The TOPOFIT method is based on the discovery of a saturation point on the alignment curve (topomax point) which presents an ability to objectively identify a border between common and variable parts in a protein structural family, providing additional insight into protein comparison and functional annotation. TOPOFIT also effectively detects nonsequential relations between protein structures. TDB provides users with the convenient ability to retrieve and analyze structural neighbors for a protein; do onetoall calculation of a user provided structure against the entire current PDB release with TServer, and pairwise comparison using the TOPOFIT method through the TPair web page. All outputs are reported in various webbased tables and graphics, with automated viewing of the structuresequence alignments in the Friend software package for complete, detailed analysis. TDB presents researchers with the opportunity for comprehensive studies of the variability in proteins and is publicly available at
Rapid detection of similarity in protein structure and function through contact metric distances
, 2006
"... ..."
Exact Algorithm for Partial Curve Matching via the Fréchet Distance
 Proc. 20th ACMSIAM Symposium on Discrete Algorithms
, 2009
"... Curve matching is a fundamental problem that occurs in many applications. In this paper, we study the problem of measuring partial similarity between curves. Specifically, given two curves, we wish to maximize the total length of subcurves that are close to each other, where closeness is measured by ..."
Abstract

Cited by 7 (3 self)
 Add to MetaCart
Curve matching is a fundamental problem that occurs in many applications. In this paper, we study the problem of measuring partial similarity between curves. Specifically, given two curves, we wish to maximize the total length of subcurves that are close to each other, where closeness is measured by the Fréchet distance, a common distance measure for curves. The resulting maximal length is called the partial Fréchet similarity between the two input curves. Given two polygonal curves P and Q in IR d of size m and n, respectively, we present the first exact algorithm that runs in polynomial time to compute Fδ(P, Q), the partial Fréchet similarity between P and Q, under the L1 and L ∞ norms. Specifically, we formulate the problem of computing Fδ(P, Q) as a longest path problem, and solve it in O(mn(m + n) log(mn)) time, under the L1 or L∞ norm, using a “shortestpath map ” type decomposition. To the best of our knowledge, this is the first paper to study this natural definition of partial curve similarity in the continuous setting (with all points in the curve considered), and present a polynomialtime exact algorithm for it. 1
Low OrderValue Optimization and Applications
, 2005
"... Given r real functions F1(x),..., Fr(x) and an integer p between 1 and r, the Low OrderValue Optimization problem (LOVO) consists of minimizing the sum of the functions that take the p smaller values. If (y1,..., yr) is a vector of data and T (x, ti) is the predicted value of the observation i with ..."
Abstract

Cited by 6 (4 self)
 Add to MetaCart
Given r real functions F1(x),..., Fr(x) and an integer p between 1 and r, the Low OrderValue Optimization problem (LOVO) consists of minimizing the sum of the functions that take the p smaller values. If (y1,..., yr) is a vector of data and T (x, ti) is the predicted value of the observation i with the parameters x ∈ IR n, it is natural to define Fi(x) = (T (x, ti) − yi) 2 (the quadratic error at observation i under the parameters x). When p = r this LOVO problem coincides with the classical nonlinear leastsquares problem. However, the interesting situation is when p is smaller than r. In that case, the solution of LOVO allows one to discard the influence of an estimated number of outliers. Thus, the LOVO problem is an interesting tool for robust estimation of parameters of nonlinear models. When p ≪ r the LOVO problem may be used to find hidden structures in data sets. One of the best succeeded applications include the Protein Alignment problem. Fully documented algorithms for this application are available at www.ime.unicamp.br/∼martinez/lovoalign. In this paper optimality conditions are discussed, algorithms for solving the LOVO problem are introduced and convergence theorems are proved. Finally, numerical experiments are presented.
doi:10.1093/nar/gkn285 Superimposé: a 3D structural superposition server
, 2008
"... The Superimposé webserver performs structural similarity searches with a preference towards 3D structurebased methods. Similarities can be detected between small molecules (e.g. drugs), parts of large structures (e.g. binding sites of proteins) and entire proteins. For this purpose, a number of alg ..."
Abstract

Cited by 5 (1 self)
 Add to MetaCart
The Superimposé webserver performs structural similarity searches with a preference towards 3D structurebased methods. Similarities can be detected between small molecules (e.g. drugs), parts of large structures (e.g. binding sites of proteins) and entire proteins. For this purpose, a number of algorithms were implemented and various databases are provided. Superimposé assists the user regarding the selection of a suitable combination of algorithm and database. After the computation on our server infrastructure, a visual assessment of the results is provided. The structurebased in silico screening for similar druglike compounds enables the detection of
Continuous Optimization Methods for Structural Alignment
 Mathematical Programming
, 2007
"... Structural Alignment is an important tool for fold identification of proteins, structural screening on ligand databases, pharmacophore identification and other applications. In the general case, the optimization problem of superimposing two structures is nonsmooth and nonconvex, so that most popular ..."
Abstract

Cited by 4 (2 self)
 Add to MetaCart
Structural Alignment is an important tool for fold identification of proteins, structural screening on ligand databases, pharmacophore identification and other applications. In the general case, the optimization problem of superimposing two structures is nonsmooth and nonconvex, so that most popular methods are heuristic and do not employ derivative information. Usually, these methods do not admit convergence theories of practical significance. In this work it is shown that the optimization of the superposition of two structures may be addressed using continuous smooth minimization. It is proved that, using a Low OrderValue Optimization approach, the nonsmoothness may be essentially ignored and classical optimization algorithms may be used. Within this context, a GaussNewton method is introduced for structural alignments incorporating (or not) transformations (as flexibility) on the structures. Convergence theorems are provided and practical aspects of implementation are described. Numerical experiments suggest that the GaussNewton methodology is competitive with stateoftheart algorithms for protein alignment both in terms of quality and speed. Additional experiments on binding site identification, ligand and cofactor alignments illustrate the generality of this approach.
BioMed Central
, 2006
"... A novel approach to phylogenetic tree construction using stochastic optimization and clustering ..."
Abstract

Cited by 4 (2 self)
 Add to MetaCart
A novel approach to phylogenetic tree construction using stochastic optimization and clustering