PSSM logo representation of results for PKC-δ and PKC-ζ. (a) PSSM logo for PKC-δ. This PSSM logo is a “graph” of the scores in the PKC-δ PSSM in Fig. 1b. Each stack of letters represents log scores for residues at a single substrate position; for example, the P+2 column (boxed) is derived from scores shown in Fig. 1a. The height of each letter is proportional to the absolute value of the residue's log score, and the positions of the letters in the stack are sorted from bottom to top in ascending value by the log score. Thus, strongly favored residues are at the top and strongly disfavored residues are at the bottom; residues that are neither strongly favored nor disfavored are minimized in visual importance. Each residue code is colored to indicate its residue's physicochemical properties: blue, basic; red, acidic; black, hydrophobic; and yellow, P. (b) PSSM logo for PKC-ζ. Black arrow, disfavored residue L analyzed in Fig. 4.