Figure 4.
Figure 4. Structure of the Np Decamer within Crystals(A)
The Np decamer is shown, as viewed along the 5-fold axis. The
two pentamers are offset by vert,
similar 15°, and individual monomers within the top and
bottom pentamers are labeled A′–E′ and A–E,
respectively.(B) The Np decamer has an hourglass shape when
viewed from the side, along a 2-fold axis. Localized negative
charges are present near the pentamer-pentamer interface. In
addition, a pair of opposing Lys57 residues are marked with an
asterisk (see [D] and [F]).(C) A surface view of the Np pentamer
is shown from within the pentamer-pentamer interface.
Alternating positive (blue) and negative (red) charges that
arise from Lys82 and Asp58 form an inner ring (black dots with
white circles). At higher radius, Lys57 and Glu59 from
the AKDE motif are revealed (see labeling key). The β hairpins
form a distinctive projection.(D) A side view is shown of two Np
monomers that face each other across the pentamer-pentamer
interface. Lys82 and Asp58 form a pair of water-mediated,
charge-based interactions that span the interface. In addition,
Lys57 and Glu59 form an intramonomer salt bridge (see [F]).(E) A
close-up is shown of a pair of charge-based interactions formed
by Lys82, Asp58, and intervening waters.(F) A close-up is shown
of an intramonomer salt bridge formed by Lys57, Glu59, and a
bound water molecule. This salt bridge may neutralize
potentially destabilizing interactions between opposing Lys57
residues (see [B] and [D])
The above figure is reprinted
by permission from Cell Press:
Mol Cell
(2001,
8,
841-853)
copyright 2001.
vert,
similar 15°, and individual monomers within the top and
bottom pentamers are labeled A′–E′ and A–E,
respectively.(B) The Np decamer has an hourglass shape when
viewed from the side, along a 2-fold axis. Localized negative
charges are present near the pentamer-pentamer interface. In
addition, a pair of opposing Lys57 residues are marked with an
asterisk (see [D] and [F]).(C) A surface view of the Np pentamer
is shown from within the pentamer-pentamer interface.
Alternating positive (blue) and negative (red) charges that
arise from Lys82 and Asp58 form an inner ring (black dots with
white circles). At higher radius, Lys57 and Glu59 from
the AKDE motif are revealed (see labeling key). The β hairpins
form a distinctive projection.(D) A side view is shown of two Np
monomers that face each other across the pentamer-pentamer
interface. Lys82 and Asp58 form a pair of water-mediated,
charge-based interactions that span the interface. In addition,
Lys57 and Glu59 form an intramonomer salt bridge (see [F]).(E) A
close-up is shown of a pair of charge-based interactions formed
by Lys82, Asp58, and intervening waters.(F) A close-up is shown
of an intramonomer salt bridge formed by Lys57, Glu59, and a
bound water molecule. This salt bridge may neutralize
potentially destabilizing interactions between opposing Lys57
residues (see [B] and [D])