TY - JOUR
T1 - Reconstitution of the photosystem I complex from the P700 and Fx-containing reaction center core protein and the FA/FB polypeptide
AU - Golbeck, John H.
AU - Mehari, Tetemke
AU - Parrett, Kevin
AU - Ikegami, Isamu
N1 - Funding Information:
Acknowledgements: This material is based upon work supported by the Cooperative State Research Service, US Department of Agriculture under Agreement no.87-CRCR-l-2382 to J.H.G. 1.1. acknowledges a grant from the Japanese government under the US-Japan Cooperative Photoconversion and Photosynthesis Research Program. The authors thank Dr Richard Malkin for essential advice and for supplying a sample of authentic FA/FB protein.
PY - 1988/11/21
Y1 - 1988/11/21
N2 - Complete restoration of electron flow from P700 to FA/FB was achieved by incubating a P700 and Fx-containing photosystem (PS) I core protein from Synechococcus sp. 6301 with the 8.9 kDa, FA/FB polypeptide from spinach. The ESR spectrum of the reconstituted PS I complex shows nearly equal photochemical reduction of FA and FB when frozen in darkness and illuminated at 16 K. When illuminated during freezing, both FA and FB are quantitatively reduced and the spectrum is nearly indistinguishable from FA and FB in the control PS I complex. In the reconstituted PS I complex Fx is photochemically reduced only in the presence of F-A and F-B, and the high-field resonance appears indistinguishable from Fx in the control PS I complex. Optical flash photolysis after extensive washing confirms the complete restoration of the P700+ [FA/FBI-back-reaction, indicating quantitative rebinding of the 8.9 kDA polypeptide. This procedure represents the first reconstitution of the PS I complex from a purified PS I core protein and an isolated 8.9 kDa, FA/FB polypeptide, and makes possible independent manipulation of the two subunits that carry the entire electron acceptor system of PS I.
AB - Complete restoration of electron flow from P700 to FA/FB was achieved by incubating a P700 and Fx-containing photosystem (PS) I core protein from Synechococcus sp. 6301 with the 8.9 kDa, FA/FB polypeptide from spinach. The ESR spectrum of the reconstituted PS I complex shows nearly equal photochemical reduction of FA and FB when frozen in darkness and illuminated at 16 K. When illuminated during freezing, both FA and FB are quantitatively reduced and the spectrum is nearly indistinguishable from FA and FB in the control PS I complex. In the reconstituted PS I complex Fx is photochemically reduced only in the presence of F-A and F-B, and the high-field resonance appears indistinguishable from Fx in the control PS I complex. Optical flash photolysis after extensive washing confirms the complete restoration of the P700+ [FA/FBI-back-reaction, indicating quantitative rebinding of the 8.9 kDA polypeptide. This procedure represents the first reconstitution of the PS I complex from a purified PS I core protein and an isolated 8.9 kDa, FA/FB polypeptide, and makes possible independent manipulation of the two subunits that carry the entire electron acceptor system of PS I.
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U2 - 10.1016/0014-5793(88)80331-4
DO - 10.1016/0014-5793(88)80331-4
M3 - Article
AN - SCOPUS:0002933688
VL - 240
SP - 9
EP - 14
JO - FEBS Letters
JF - FEBS Letters
SN - 0014-5793
IS - 1-2
ER -