Figure 1
From: Evolutionarily conserved bias of amino-acid usage refines the definition of PDZ-binding motif
Preferential localization of two-position-specified PB motifs at C-terminal ends of proteins. Diagram on the top shows how positions (0, -1, -2, -3, -4) in a five-AA long PB motif are defined. Position 0 is defined as the last AA of the motif toward the C-terminal end. C0: the PB motif is located at the C-terminal end, C1: one AA away, and C50: fifty AAs away from the C-terminal end. (a-h) The "ratio" indicates the number of genes identified at each C0 to C50 position divided by the number at C0. The AAs at positions 0 and -2 are specified at the upper left in each graph. AAs are indicated with single letter code (S, serine; T, threonine; I, isoleucine; L, leucine; V, valine). × denotes any AA. Curves for the five species are shown in different colors.