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Figure 5.
Fig. 5. β-Sheet superstructures in the crystal structures of
(a) wild-type λ Cro (5CRO) and (b) PSQ form 2. The two views in
(a) illustrate the closed 12-stranded tetrametric β-barrel
formed by the two dimers in the asymmetric unit of the wild-type
λ Cro structure. (b) shows five symmetry-related dimers of PSQ,
which illustrate the infinite corkscrew of β-structure along
one crystal axis. The picture is oriented so that the leftmost
PSQ dimer in (b) may be compared to the wild-type dimer in the
foreground of the left half of (a). Each dimer in PSQ form 2
interacts with two other symmetry-related dimers, while in
wild-type Cro, each dimer interacts with only one other dimer.
Loops at the N- and C-termini of all structures are omitted for
clarity. This figure was generated using PyMOL.
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