title: Application of compression-based distance measures to protein sequence classification: a methodological study.
abstract: BACKGROUND
  Distance measures built on the notion of text compression have been used for the comparison and classification of entire genomes and mitochondrial genomes. The present study was undertaken in order to explore their utility in the classification of protein sequences.
  
  
  RESULTS
  We constructed compression-based distance measures (CBMs) using the Lempel-Zlv and the PPMZ compression algorithms and compared their performance with that of the Smith-Waterman algorithm and BLAST, using nearest neighbour or support vector machine classification schemes. The datasets included a subset of the SCOP protein structure database to test distant protein similarities, a 3-phosphoglycerate-kinase sequences selected from archaean, bacterial and eukaryotic species as well as low and high-complexity sequence segments of the human proteome, CBMs values show a dependence on the length and the complexity of the sequences compared. In classification tasks CBMs performed especially well on distantly related proteins where the performance of a combined measure, constructed from a CBM and a BLAST score, approached or even slightly exceeded that of the Smith-Waterman algorithm and two hidden Markov model-based algorithms.
authors.affiliation: Research Group on Artificial Intelligence of the Hungarian Academy of Sciences and University of Szeged Aradi vértanúk tere 1., H-6720 Szeged, Hungary. kocsor@inf.u-szeged.hu
authors.forename: András
authors.initials: A
authors.lastname: Kocsor
authors.forename: Attila
authors.initials: A
authors.lastname: Kertész-Farkas
authors.forename: László
authors.initials: L
authors.lastname: Kaján
authors.forename: Sándor
authors.initials: S
authors.lastname: Pongor
mesh_terms: D000465:Algorithms; D000595:Amino Acid Sequence; D044962:Data Compression / Q000379:methods*; D008969:Molecular Sequence Data; D011506:Proteins / Q000032:analysis / Q000737:chemistry* / Q000145:classification*; D016415:Sequence Alignment / Q000379:methods*; D020539:Sequence Analysis, Protein / Q000379:methods*
chemical_list: D011506:Proteins