Figure 3
From: Statistical distributions of optimal global alignment scores of random protein sequences
Distribution of scores from global alignments of the SMP sequence set of 300aa long. The alignments were carried out with the PAM120 matrix and an affine gap penalty of -16 and -4. The distribution of the scores was fitted with three distribution curves indicated by the solid line. (A) The scores were fitted with the gamma distribution. The fitted parameters are: γ = 3294940, λ = 31.7263, μ = -103798, χ2 value is 10.8053 with d.f. = 12; (B) The scores were fitted with the normal distribution. The fitted parameters are: σ = 57.2142, μ = 56.5328; d.f. = 13, χ2 = 11.0862; (C) The scores were fitted with the Gumbel distribution. The fitted parameters are: β = 44.6098, μ = 30.7864; d.f. = 13, χ2 = 21244.1.