Identification of the Plastocyanin Binding Subunit of Photosystem I

  • Michael Hippler
  • Rafael Ratajczak
  • Wolfgang Haehnel


A photosystem (PS) I complex being competent in mediating the electron transfer from plastocyanin (PCy) to ferredoxin is assembled from more than 7 subunits [1]. The two large chlorophyll (chl) a containing subunits Ia and Ib are plastid encoded and carry the primary electron donor P700 and the electron acceptors A0, phylloquinone and Fe-SX. Subunit VII carries the electron acceptors Fe-SA and Fe-SB (reviewed in [2]). Subunit II has been shown by cross-linking to ensure the docking of ferredoxin to subunit VII [3], Subunit III appeared to be necessary for the electron transfer from PCy to PS I [1]. This subunit does not carry a prosthetic group [4] and it is positively charged [5]. Its attribution to a band in SDS-PAGE is ambiguous because subunit III and IV alter their relative position in different gel systems [6]. Subunit III has been suggested to be identical with a subunit of 21 kDa [7] or a positively charged subunit of 9.7 kDa as deduced from the gene sequence [8]. Several authors have questioned a role of subunit III. However, in a recent study [9] PCy was cross-linked to a PS I subunit of 19 kDa. The function of this subunit and the assignment to one of the PS I subunits remains to be established.


Methyl Viologen Primary Electron Donor Stroma Lamella Negative Surface Charge Density Peptide Deduce Sequence 
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  1. [1]
    Bengis, C. and Nelson, N. (1977) J. Biol. Chem. 252, 4564–4569PubMedGoogle Scholar
  2. [2]
    Malkin, R. (1987) In: The Light Reactions. Topics in Photosynthesis, Vol. 8 (Barber, J., ed.), pp. 495–525, Elsevier, AmsterdamGoogle Scholar
  3. [3]
    Zanetti, G. and Merati, G. (1987) Eur. J. Biochem. 169, 143–146PubMedCrossRefGoogle Scholar
  4. [4]
    Haehnel, W., Hesse, V. and Pröpper, A. (1980) FEBS Lett. 111,79–82CrossRefGoogle Scholar
  5. [5]
    Ratajczak, R., Mitchell, R. and Haehnel, W. (1988) Biochim. Biophys. Acta 933,306–318CrossRefGoogle Scholar
  6. [6]
    Nechushtai, R., Nelson, N., Mattoo, A. K. and Edelman, M. (1981) FEBS Lett. 125,115–119CrossRefGoogle Scholar
  7. [7]
    Dunn, P. P. J., Packman, L. C., Pappin, D. and Gray, J. C. (1988) FEBS Lett. 228,157–161PubMedCrossRefGoogle Scholar
  8. [8]
    Münch, S., Ljungberg, U., Steppuhn, J., Schneiderbauer, A., Nechushtai, R., Beyreuther, K., Herrmann, R. G. (1988) Curr. Genet. 14,511–518PubMedCrossRefGoogle Scholar
  9. [9]
    Wynn, R. M. and Malkin, R. (1988) Biochemistry 27,5863–5869PubMedCrossRefGoogle Scholar
  10. [10]
    Andersson, B., Åkerlund, H.-E. and Albertsson, P.-Å. (1976) Biochim. Biophys. Acta 423, 122–132PubMedCrossRefGoogle Scholar
  11. [II]
    Laemmli, U. K. (1970) Nature 227, 680–685PubMedCrossRefGoogle Scholar
  12. [12]
    Haehnel, W., Ratajczak, R. and Robenek, H. (1989) J. Cell Biol. 108, 1397–1405PubMedCrossRefGoogle Scholar
  13. [13]
    Chua, N.-H. (1980) Methods Enzymol. 69, 434–446CrossRefGoogle Scholar
  14. [14]
    Steppuhn, J., Hermans, J., Nechushtai, R., Ljungberg, U., Thümmler, F., Lottspeich, F. and Herrmann, R. G. (1988) FEBS Lett. 237, 218–224PubMedCrossRefGoogle Scholar
  15. [15]
    Haehnel, W., Pröpper, A. and Krause, H. (1980) Biochim. Biophys. Acta 593, 384–399PubMedCrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 1990

Authors and Affiliations

  • Michael Hippler
    • 1
  • Rafael Ratajczak
    • 1
  • Wolfgang Haehnel
    • 1
  1. 1.Lehrstuhl für Biochemie der Pflanzen, Lehrstuhl für Medizinische CytologieUniversity of MünsterMünsterFederal Republic of Germany

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