TY - JOUR
T1 - Solution structure of a biological bimolecular electron transfer complex
T2 - Characterization of the photosynthetic reaction center-cytochrome c2 protein complex by small angle neutron scattering
AU - Tiede, D. M.
AU - Littrell, K.
AU - Marone, P. A.
AU - Zhang, R.
AU - Thiyagarajan, P.
PY - 2000
Y1 - 2000
N2 - The structures of kinetically distinct electron transfer complexes formed between the photosynthetic reaction center from Rhodobacter sphaeroides R-26, and a water-soluble cytochrome c2 were characterized using small angle neutron scattering, SANS. Reaction center-cytochrome c2 complexes, RC-C, exhibiting predominately single exponential electron transfer kinetics were found to be 1:1 molar complexes, consistent with a low resolution, co-crystal, x-ray structure (Adir et al., 1996), provided that the cofactor separation was adjusted to 14 ± 3 Å. Other RC-C configurations are consistent with SANS data, but are distinguishable by cofactor separation. RC-C preparations exhibiting more complex kinetics were found to have a particle volume markedly greater than that of a 1:1 complex. These results suggest that RC aggregation is associated with the variation in kinetics reported in the literature, and provide evidence that the model for the 1:1 complex in co-crystals is relevant to the solution environment.
AB - The structures of kinetically distinct electron transfer complexes formed between the photosynthetic reaction center from Rhodobacter sphaeroides R-26, and a water-soluble cytochrome c2 were characterized using small angle neutron scattering, SANS. Reaction center-cytochrome c2 complexes, RC-C, exhibiting predominately single exponential electron transfer kinetics were found to be 1:1 molar complexes, consistent with a low resolution, co-crystal, x-ray structure (Adir et al., 1996), provided that the cofactor separation was adjusted to 14 ± 3 Å. Other RC-C configurations are consistent with SANS data, but are distinguishable by cofactor separation. RC-C preparations exhibiting more complex kinetics were found to have a particle volume markedly greater than that of a 1:1 complex. These results suggest that RC aggregation is associated with the variation in kinetics reported in the literature, and provide evidence that the model for the 1:1 complex in co-crystals is relevant to the solution environment.
UR - http://www.scopus.com/inward/record.url?scp=0034496667&partnerID=8YFLogxK
U2 - 10.1107/S0021889800099891
DO - 10.1107/S0021889800099891
M3 - Article
AN - SCOPUS:0034496667
SN - 0021-8898
VL - 33
SP - 560
EP - 564
JO - Journal of Applied Crystallography
JF - Journal of Applied Crystallography
IS - 3 I
ER -