Protein fold recognition using genetic algorithm optimized voting scheme and profile bigram

In biology, identifying the tertiary structure of a protein helps determine its functions. A step towards tertiary structure identification is predicting a protein’s fold. Computational methods have been applied to determine a protein’s fold by assembling information from its structural, physicochemical and/or evolutionary properties. It has been shown that evolutionary information helps improve prediction accuracy. In this study, a scheme is proposed that uses the genetic algorithm (GA) to optimize a weighted voting scheme to improve protein fold recognition. This scheme incorporates k-separated bigram transition probabilities for feature extraction, which are based on the Position Specific Scoring Matrix (PSSM). A set of SVM classifiers are used for initial classification, whereupon their predictions are consolidated using the optimized weighted voting scheme. This scheme has been demonstrated on the Ding and Dubchak (DD), Extended Ding and Dubchak (EDD) and Taguchi and Gromhia (TG) datasets benchmarked data sets

A mixture of physicochemical and evolutionary–based feature extraction approaches for protein fold recognition

Griffith Sciences, Griffith School of EngineeringFull Tex

Predicting Protein Contact Map By Bagging Decision Trees

Proteins\u27 function and structure are intrinsically related. In order to understand proteins\u27 functionality, it is essential for medical and biological researchers to deter- mine proteins\u27 three-dimensional structure. The traditional method using NMR spectroscopy or X-ray crystallography are inefficient compared to computational methods. Fortunately, substantial progress has been made in the prediction of protein structure in bioinformatics. Despite these achievements, the computational complexity of protein folding remains a challenge. Instead, many methods aim to predict a protein contact map from protein sequence using machine learning algorithms. In this thesis, we introduce a novel ensemble method for protein contact map prediction based on bagging multiple decision trees. A random sampling method is used to address the large class imbalance in contact maps. To generalize the feature space, we further clustered the amino acid alphabet from twenty to ten. A software is also developed to view protein contact map at certain threshold and separation. The parameters used in decision trees are determined experimentally, and the overall results for the first L, L/2 and L/5 predictions for protein of length L are evaluated