Correlation of structural and spectroscopic properties of a photosynthetic reaction center

Polarized spectra of absorption and light-induced absorbance
changes are presented for the crystallized reaction centers of
Rhodopseudomonas viridis. We find that a model based on extended
dipole interaction between all six pigments is capable of
interpreting detailed features such as the contributions from the
individual pigments to the various absorption peaks. Even though
the pigments are arranged in approximate C2 symmetry, the optical
spectra together with the calculations reflect deviations from this
symmetry, which may be important in understanding the electron
pathway.