Structure of
USP11 N-terminal DUSP-UBL domains. (A) Schematic representation
of the USP11 domain structure. (B) Cartoon representation depicting
human USP11DU in a dimeric domain swapped arrangement as observed
in the crystallographic asymmetric unit. The second copy is labeled
as ′. The DUSP domains from each chain are shown in green,
the UBL domains are in purple, and the linker region, residues 141–152,
is shown in cyan. (C) Close-up view of the DUSP–linker interaction
in hUSP11. Note the VEVY motif, part of the linker region shown in
cyan and the hydrophobic nature of side chains in the DUSP domain,
shown in green. H-bonding interactions are indicated as dashed lines.
(D) Cartoon depicting monomeric rat USP11DU in the same orientation
as hUSP11DU in (B). The DUSP domain depicted in green stacks against
the UBL domain from the same chain, shown in purple. This arrangement
is mediated by the linker region, residues 133–144, which forms
a β-hairpin structure denoted the DU finger. Key residues and
sequence segments are labeled. (E) Cartoon depicting the hydrophobic
DUSP-linker interface. The rUSP11 DUSP surface is colored according
to sequence conservation between USP11 from human and rat. Identical
residues are colored orange, residues that display similar properties
are shown in yellow, and residues that are weakly similar in light
gray and dissimilar in dark gray.