Comparison of USP4, USP15 and USP11 features. The red, blue and green boxes arranged in a circle represent USP4, USP15 and USP11, respectively. Domain structures are marked as follows: DUSP, domain in USP (N-terminal domain specific to these USPs); UBL, ubiquitin-like domain; D1 & D2, bi-part catalytic domain mediating ubiquitin cleavage. The interior of the circle links amino acid identities among paralogs, where each line represents an identical aligned residue. Links are colored as follows: USP4-USP15 purple; USP11-USP15 teal; USP4-USP11 gold. Alignment links are separated into two outer rings to facilitate viewing. The exterior of the circle features two rings illustrating the following: Inner ring: orthologous protein conservation. The histogram shows site-specific entropy among vertebrate species in black. High entropy reflects high dissimilarity. For comparative measure, the number of species containing the aligned region in question is below the histogram in gray. Low species count indicates amino acid indels. Outer ring: GC content. The heat map indicates relative GC content at the third codon position (GC3), where high GC content is red and low GC content is blue.