TY - JOUR
T1 - Functional subunit structure of photosystem 1 reaction center in Synechococcus sp
AU - Takahashi, Yuichiro
AU - Katoh, Sakae
N1 - Funding Information:
’ This research was supported in part by a grant from the Toray Science Foundation and the Grants-in-Aid for Science Research from the Ministry of Education, Science and Culture, Japan to S.K. ’ To whom all correspondence should be addressed. ’ Abbreviations used: PS 1, photosystem 1; SDS, sodium dodecyl sulfate; Tris, tris(hydroxyl-methylkmkomethane.
PY - 1982/11
Y1 - 1982/11
N2 - Photochemical activities of six different P700-chlorophyll a-proteins (CP1-a, -b1, -b2, -c, -d, and -e) separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis from digitonin particles of a thermophilic cyanobacterium Synechococcus sp. were examined. CP1-a, -b1, -b2, and -c contain the competent reaction center of photosystem 1: They were highly active in photooxidation of cytochrome c-553, the physiological electron donor to P700 in the organism, with methyl viologen as electron acceptor and showed flash-induced absorption changes indicating the charge separation between P700 and the secondary electron acceptors, P430 and A2. The cytochrome photooxidation and P430 and A2 photoresponses were significantly suppressed in CP1-d. CP1-e which lacks P430 and A2 was least active in the cytochrome photooxidation. A1, the primary electron acceptor of P700, is present in CP1-e as well as in other CP1 complexes. Comparison of the results with the polypeptide composition of CP1 complexes (Y. Takahashi, H. Koike, and S. Katoh, 1982, Arch. Biochem. Biophys.219, 209-218). indicates that CP1-c which contains four polypeptides with molecular weights of 62,000, 60,000, 14,000, and 10,000 represents the functional core of the photosystem 1 reaction center. P700, A1, and antenna chlorophyll are associated with 62,000- and 60,000-dalton polypeptides, whereas 14,000- and 10,000-dalton polypeptides are assumed to carry P430 and A2. The 13,000-dalton polypeptide which is associated with CP1-a, -b1, and -b2 is not required for the functioning of the reaction center.
AB - Photochemical activities of six different P700-chlorophyll a-proteins (CP1-a, -b1, -b2, -c, -d, and -e) separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis from digitonin particles of a thermophilic cyanobacterium Synechococcus sp. were examined. CP1-a, -b1, -b2, and -c contain the competent reaction center of photosystem 1: They were highly active in photooxidation of cytochrome c-553, the physiological electron donor to P700 in the organism, with methyl viologen as electron acceptor and showed flash-induced absorption changes indicating the charge separation between P700 and the secondary electron acceptors, P430 and A2. The cytochrome photooxidation and P430 and A2 photoresponses were significantly suppressed in CP1-d. CP1-e which lacks P430 and A2 was least active in the cytochrome photooxidation. A1, the primary electron acceptor of P700, is present in CP1-e as well as in other CP1 complexes. Comparison of the results with the polypeptide composition of CP1 complexes (Y. Takahashi, H. Koike, and S. Katoh, 1982, Arch. Biochem. Biophys.219, 209-218). indicates that CP1-c which contains four polypeptides with molecular weights of 62,000, 60,000, 14,000, and 10,000 represents the functional core of the photosystem 1 reaction center. P700, A1, and antenna chlorophyll are associated with 62,000- and 60,000-dalton polypeptides, whereas 14,000- and 10,000-dalton polypeptides are assumed to carry P430 and A2. The 13,000-dalton polypeptide which is associated with CP1-a, -b1, and -b2 is not required for the functioning of the reaction center.
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U2 - 10.1016/0003-9861(82)90152-7
DO - 10.1016/0003-9861(82)90152-7
M3 - Article
C2 - 6295282
AN - SCOPUS:0020210904
VL - 219
SP - 219
EP - 227
JO - Archives of Biochemistry and Biophysics
JF - Archives of Biochemistry and Biophysics
SN - 0003-9861
IS - 1
ER -