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Figure 4.
Figure 4. Comparison of the Fold of the Noncatalytic Domain
of Prolyl Oligopeptidase with a Typical β-Propeller
Structure(A) The protein chain of the β-propeller domain of
prolyl oligopeptidase is colored as in Figure 2 and viewed
perpendicular to that, down the pseudo 7-fold axis. The β
sheets of the seven blades are joined in succession (β1/1 to
β7/4, cf. Figure 1) around the central axis. The “Velcro”
is not closed; there are only hydrophobic interactions between
the first (blue) and last (green) blades. Residues (Lys82,
Glu134, His180, Asp242, Lys389, and Lys390) narrowing the
entrance to the tunnel of the propeller are shown in a
ball-and-stick representation.(B) The structure of G-protein β
subunit (PDB entry 1tbg). The “Velcro” is closed between the
two termini of the polypeptide chain by the main chain hydrogen
bonds between the N terminus (blue) and the three antiparallel
β strands from the C terminus (green). (Drawn with MolScript
and rendered with Raster3D.)
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