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Figure 8.
Figure 8. A Schematic Diagram Showing Possible Oligomeric
Forms of TRAP3 Protein
Monomer equivalents are shown as
blue blocks, and their N and C termini equivalents are marked as
N and C respectively. The peptide linkers (Ala-Ala-Ala-Met)
shown in red connect the C-terminal residue of one monomer to
the N-terminal residue of the next. In wild-type TRAP, the N and
C termini lie at opposite faces of the ring, with the N-terminal
residue pointing into the cavity and the C-terminal residue
lying on the outer surface of the ring. The distance between the
last visible N- and C-terminal residues in the wild-type
structure (Ser5 and Lys73 respectively) is 37.8 Å. In
TRAP3 and TRAP4, peptide loops (not visible in the electron
density) connect the monomer equivalents as shown. (A) In the
12-mer ring form observed in the crystal, the peptide linkers
must cross from one face of the ring to the other, as shown by
the red lines. (B) An unstrained, imaginary form of TRAP3 in
which the peptide linkers lie parallel, so that their folded
domains (shown as blue blocks) can associate into three TRAP
11-mer rings essentially identical to wild-type TRAP rings,
giving the form shown in (C), the imaginary tube-like form of
TRAP3.
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