title: Predicting protein subcellular locations using hierarchical ensemble of Bayesian classifiers based on Markov chains.
abstract: BACKGROUND
  The subcellular location of a protein is closely related to its function. It would be worthwhile to develop a method to predict the subcellular location for a given protein when only the amino acid sequence of the protein is known. Although many efforts have been made to predict subcellular location from sequence information only, there is the need for further research to improve the accuracy of prediction.
  
  
  RESULTS
  A novel method called HensBC is introduced to predict protein subcellular location. HensBC is a recursive algorithm which constructs a hierarchical ensemble of classifiers. The classifiers used are Bayesian classifiers based on Markov chain models. We tested our method on six various datasets; among them are Gram-negative bacteria dataset, data for discriminating outer membrane proteins and apoptosis proteins dataset. We observed that our method can predict the subcellular location with high accuracy. Another advantage of the proposed method is that it can improve the accuracy of the prediction of some classes with few sequences in training and is therefore useful for datasets with imbalanced distribution of classes.
  
  
  CONCLUSIONS
  This study introduces an algorithm which uses only the primary sequence of a protein to predict its subcellular location. The proposed recursive scheme represents an interesting methodology for learning and combining classifiers. The method is computationally efficient and competitive with the previously reported approaches in terms of prediction accuracies as empirical results indicate. The code for the software is available upon request.
authors.affiliation: Theoretical Bioinformatics Department, German Cancer Research Center, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany. A.Bulashevska@dkfz.de
authors.forename: Alla
authors.initials: A
authors.lastname: Bulashevska
authors.forename: Roland
authors.initials: R
authors.lastname: Eils
mesh_terms: D000595:Amino Acid Sequence; D001499:Bayes Theorem; D008390:Markov Chains; D008954:Models, Biological; D008956:Models, Chemical; D008958:Models, Molecular; D015233:Models, Statistical; D008969:Molecular Sequence Data; D011506:Proteins / Q000737:chemistry* / Q000378:metabolism*; D016415:Sequence Alignment / Q000379:methods*; D020539:Sequence Analysis, Protein / Q000379:methods*; D013329:Structure-Activity Relationship; D013347:Subcellular Fractions / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D011506:Proteins