|
Figure 6.
Figure 6. Diagram of the IκB/NF-κB Complex, Showing
Additional Interactions and Relative Positions of Domains Not
Included in the Crystal StructureSpace-filling representations
of the ankyrin domain of IκBα and of the RHRs of p65 and p50
are shown, with strands to represent N- or C-terminal
extensions. The C-terminal extension of p65 includes segments
likely to interact with the transcription machinery. The C
terminus of p50 following the NLS is a glycine-rich tail. In
p105, this tail connects to an IκB domain. The figure shows
that this connection can be a simple loop. The N-terminal 69
residues of IκBα include the sites for phosphorylation and
ubiquitination as well as residues thought to mask the p50 NLS.
The C-terminal extension of IκBα occludes the DNA-binding
site; it contains a proline, glutamic-acid, serine, and
threonine-rich segment (PEST domain), which regulates basal
turnover ([59]). The color scheme conforms to Figure 1. Features
with labels in colored boxes are parts of the complex not
present or not ordered in the crystal structure. The p50 RHR-n
has been modeled in an orientation, relative to p50 RHR-c,
similar to the orientation of p65 RHR-n relative to p65 RHR-c in
the structure. Both of the RHR N-terminal domains may actually
adopt a variety of orientations, due to the flexibility of the
RHR linker. Figures made with the program RIBBONS ( [13]).
|
