title: Amino acid substitution matrices from protein blocks.
abstract: Methods for alignment of protein sequences typically measure similarity by using a substitution matrix with scores for all possible exchanges of one amino acid with another. The most widely used matrices are based on the Dayhoff model of evolutionary rates. Using a different approach, we have derived substitution matrices from about 2000 blocks of aligned sequence segments characterizing more than 500 groups of related proteins. This led to marked improvements in alignments and in searches using queries from each of the groups.
authors.affiliation: Howard Hughes Medical Institute, Fred Hutchinson Cancer Research Center, Seattle, WA 98104.
authors.forename: S
authors.initials: S
authors.lastname: Henikoff
authors.forename: J G
authors.initials: JG
authors.lastname: Henikoff
mesh_terms: D000465:Algorithms; D000595:Amino Acid Sequence; D000818:Animals; D017173:Caenorhabditis elegans / Q000235:genetics; D004330:Drosophila / Q000235:genetics; D008126:Lod Score; D008433:Mathematics; D008969:Molecular Sequence Data; D011336:Probability; D011506:Proteins / Q000737:chemistry / Q000235:genetics*; D017386:Sequence Homology, Amino Acid; D012984:Software
chemical_list: D011506:Proteins