Skip to main content
PMC home page
Proceedings of the National Academy of Sciences of the United States of America logoLink to Proceedings of the National Academy of Sciences of the United States of America
. 1990 Aug;87(15):5682–5686. doi: 10.1073/pnas.87.15.5682

Stark spectroscopy of the Rhodobacter sphaeroides reaction center heterodimer mutant.

S L Hammes 1, L Mazzola 1, S G Boxer 1, D F Gaul 1, C C Schenck 1
PMCID: PMC54391  PMID: 2198569

Abstract

The effect of an electric field has been measured on the absorption spectrum (Stark effect) of the heterodimer mutant (M)H202L of Rhodobacter sphaeroides reaction centers, where the primary electron donor consists of one bacteriochlorophyll alpha and one bacteriopheophytin alpha. The electronic absorption spectrum of the heterodimer mutant from 820-950 nm is relatively featureless in a poly(vinyl alcohol) film, but it exhibits some structure in a glycerol/water glass at 77 K. A feature is seen in the Stark effect spectrum of the heterodimer at 77 K centered at 927 and 936 nm in poly(vinyl alcohol) and a glycerol/water glass, respectively. This feature has approximately the same shape and width as the Stark effect for the primary electron donor of the wild type, which consists of a pair of bacteriochlorophyll alpha molecules. The angle zeta A between the transition moment at the frequency of absorption and the difference dipole delta muA is 36 +/- 2 degrees in the wild type and 32 +/- 2 degrees for that feature in the heterodimer. A range of values for [delta muA] = (13-17)/f Debye units (where f is the local field correction) is obtained for the 936-nm feature in glycerol/water, depending on analysis method. This feature is interpreted as arising from a transition to the lower exciton state of the heterodimer, which is more strongly mixed with a low-lying charge transfer transition than in the wild type.

Full text

PDF
5682

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Allen J. P., Feher G., Yeates T. O., Komiya H., Rees D. C. Structure of the reaction center from Rhodobacter sphaeroides R-26: the cofactors. Proc Natl Acad Sci U S A. 1987 Aug;84(16):5730–5734. doi: 10.1073/pnas.84.16.5730. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Allen J. P., Feher G., Yeates T. O., Komiya H., Rees D. C. Structure of the reaction center from Rhodobacter sphaeroides R-26: the protein subunits. Proc Natl Acad Sci U S A. 1987 Sep;84(17):6162–6166. doi: 10.1073/pnas.84.17.6162. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Bylina E. J., Youvan D. C. Directed mutations affecting spectroscopic and electron transfer properties of the primary donor in the photosynthetic reaction center. Proc Natl Acad Sci U S A. 1988 Oct;85(19):7226–7230. doi: 10.1073/pnas.85.19.7226. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Chang C. H., Tiede D., Tang J., Smith U., Norris J., Schiffer M. Structure of Rhodopseudomonas sphaeroides R-26 reaction center. FEBS Lett. 1986 Sep 1;205(1):82–86. doi: 10.1016/0014-5793(86)80870-5. [DOI] [PubMed] [Google Scholar]
  5. Deisenhofer J., Epp O., Miki K., Huber R., Michel H. X-ray structure analysis of a membrane protein complex. Electron density map at 3 A resolution and a model of the chromophores of the photosynthetic reaction center from Rhodopseudomonas viridis. J Mol Biol. 1984 Dec 5;180(2):385–398. doi: 10.1016/s0022-2836(84)80011-x. [DOI] [PubMed] [Google Scholar]
  6. Fajer J., Brune D. C., Davis M. S., Forman A., Spaulding L. D. Primary charge separation in bacterial photosynthesis: oxidized chlorophylls and reduced pheophytin. Proc Natl Acad Sci U S A. 1975 Dec;72(12):4956–4960. doi: 10.1073/pnas.72.12.4956. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Kirmaier C., Holten D., Bylina E. J., Youvan D. C. Electron transfer in a genetically modified bacterial reaction center containing a heterodimer. Proc Natl Acad Sci U S A. 1988 Oct;85(20):7562–7566. doi: 10.1073/pnas.85.20.7562. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Lockhart D. J., Boxer S. G. Stark effect spectroscopy of Rhodobacter sphaeroides and Rhodopseudomonas viridis reaction centers. Proc Natl Acad Sci U S A. 1988 Jan;85(1):107–111. doi: 10.1073/pnas.85.1.107. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Lösche M., Feher G., Okamura M. Y. The Stark effect in reaction centers from Rhodobacter sphaeroides R-26 and Rhodopseudomonas viridis. Proc Natl Acad Sci U S A. 1987 Nov;84(21):7537–7541. doi: 10.1073/pnas.84.21.7537. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Taylor J. W., Ott J., Eckstein F. The rapid generation of oligonucleotide-directed mutations at high frequency using phosphorothioate-modified DNA. Nucleic Acids Res. 1985 Dec 20;13(24):8765–8785. doi: 10.1093/nar/13.24.8765. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Vermeglio A., Clayton R. K. Orientation of chromophores in reaction centers of Rhodopseudomonas sphaeroides. Evidence for two absorption bands of the dimeric primary electron donor. Biochim Biophys Acta. 1976 Dec 6;449(3):500–515. doi: 10.1016/0005-2728(76)90159-6. [DOI] [PubMed] [Google Scholar]
  12. Williams J. C., Steiner L. A., Feher G. Primary structure of the reaction center from Rhodopseudomonas sphaeroides. Proteins. 1986 Dec;1(4):312–325. doi: 10.1002/prot.340010405. [DOI] [PubMed] [Google Scholar]
  13. Youvan D. C., Ismail S., Bylina E. J. Chromosomal deletion and plasmid complementation of the photosynthetic reaction center and light-harvesting genes from Rhodopseudomonas capsulata. Gene. 1985;38(1-3):19–30. doi: 10.1016/0378-1119(85)90199-4. [DOI] [PubMed] [Google Scholar]

Articles from Proceedings of the National Academy of Sciences of the United States of America are provided here courtesy of National Academy of Sciences

RESOURCES