Databases and Comparisons - CMB Education - Karolinska Institutet

PAM, cont.PAM1 stands for 1 accepted mutation per 100residues.PAM matrices for less similar sequences areobtained by extrapolations.The PAM100 matrix corresponds to 100 acceptedmutations per 100 residues, but since the sameresidue might change more than once, twosequences with this level of mutations will haveabout 50% identities.Similarly, the PAM250 matrix corresponds to a levelof about 20% identical residues.Linköping University & Karolinska Institutet 46