X-ray structure of PSII showing all chromophores. Yellow and green,
Chls efficiently transferring excitation to the RC (yellow, most
efficient); blue, peripheral Chls not coupled directly to the RC; dark
pink, RC Chls; pale pink, RC Pheos; red, long-wavelength Chl of CP47
coordinated by His-114. Chls numbered from 9 to 21 are associated with
the CP43 polypeptide; Chls numbered from 22 to 37 are associated with
the CP47 polypeptide. (Upper) View from the stromal side
of the membrane. (Lower) Side view (stromal surface
above).