Figure 2. The properties of lysine ubiquitination sites.

(A) Probable sequence motifs for ±10 amino acids around the lysine ubiquitination sites. The central K stands for the ubiquitinated lysine and the height of each letter corresponding to the frequency of the amino acid residue in that position. (B) Heat map showing the relative frequencies of amino acids in specific positions. Red and green respectively indicate the amino acid is significantly enriched or reduced near the ubiquitinated site. (C) Probable distribution of secondary structures containing lysine ubiquitination sites. (D) Predicted surface accessibility of the ubiquitinated sites. Ubiquitinated lysine sites were in red and all lysine sites were in green.