出典:Wikipedia
出典:『Wikipedia』 (2011/06/28 13:17 UTC 版)
Point Accepted Mutation (PAM) or Percent Accepted Mutation, is a set of matrices used to score sequence alignments. The PAM matrices were introduced by Margaret Dayhoff in 1978 based on 1572 observed mutations in 71 families of closely related proteins. Each matrix has the twenty standard amino acids in its twenty rows and columns; the value in a given cell represents the probability of a substitution of one amino acid for another. This type of matrix is commonly known as a substitution matrix.