Figure 4.
Figure 4. (a) View from the stromal side. The PSI trimer is
approximately discoidal, monomers being separated by lateral
indentations. The maximal distance from the C[3] axis to the
peripheral surface is vert,
similar 105 (±5) Å. Membrane-integral subunits are
indicated in white; the subunits of the stromal ridge are
indicated in colour: PsaC, yellow, PsaD, red; PsaE, blue. The
binding pocket for ferredoxin/flavodoxin, formed by PsaC, PsaD,
PsaE and a-helix e' of either PsaA or PsaB, on the side of the
ridge distal from the C[3]-axis is indicated; asterisk: crystal
contact. (b) View along the membrane plane, i.e. view as in (a)
but flipped about the horizontal through 90°. (Produced
using Grasp; [Nicholls et al 1991].)
vert,
similar 105 (±5) Å. Membrane-integral subunits are
indicated in white; the subunits of the stromal ridge are
indicated in colour: PsaC, yellow, PsaD, red; PsaE, blue. The
binding pocket for ferredoxin/flavodoxin, formed by PsaC, PsaD,
PsaE and a-helix e' of either PsaA or PsaB, on the side of the
ridge distal from the C[3]-axis is indicated; asterisk: crystal
contact. (b) View along the membrane plane, i.e. view as in (a)
but flipped about the horizontal through 90°. (Produced
using Grasp; [Nicholls et al 1991].)