Effects of pigment-protein interactions on the conformation of the primary electron acceptor in Rhodobacter capsulatus reaction centers.
Resonance Raman spectra are reported for RCs from Rb. capsulatus in which the L104 glutamic acid is replaced by glutamine. The skeletal modes of the primary electron acceptor, BPhL, in these RCs undergo temperature-dependent frequency shifts that are identical to those observed for BPhL in RCs from wild-type. This observation suggests that the strength of the hydrogen bond between the L104 residue and the C9 keto group of BPhL is not a determinant of the temperature-dependent conformation of this pigment.
Peloquin
J M
JM
Department of Chemistry, Carnegie Mellon University, Pittsburgh, PA 15213.
Bylina
E J
EJ
Youvan
D C
DC
Bocian
D F
DF
D006860:Hydrogen Bonding; D010674:Pheophytins / Q000737:chemistry / Q000378:metabolism*; D045322:Photosynthetic Reaction Center Complex Proteins / Q000737:chemistry / Q000378:metabolism*; D011487:Protein Conformation; D016354:Rhodobacter capsulatus / Q000378:metabolism*; D013059:Spectrum Analysis, Raman; D013696:Temperature
D010674:Pheophytins; D045322:Photosynthetic Reaction Center Complex Proteins; C006678:bacteriopheophytin