The NDH-1L-PSI Supercomplex Is Important for Efficient Cyclic Electron Transport in Cyanobacteria.
Two mutants isolated from a tagging library of Synechocystis sp. strain PCC 6803 were sensitive to high light and had a tag in sll1471 encoding CpcG2, a linker protein for photosystem I (PSI)-specific antenna. Both mutants demonstrated strongly impaired NDH-1-dependent cyclic electron transport. Blue native-polyacrylamide gel electrophoresis followed by immunoblotting and mass spectrometry analyses of the wild type and a mutant containing CpcG2 fused with yellow fluorescent protein-histidine6 indicated the presence of a novel NDH-1L-CpcG2-PSI supercomplex, which was absent in the cpcG2 deletion mutant, the PSI-less mutant, and several other strains deficient in NDH-1L and/or NDH-1M. Coimmunoprecipitation and pull-down analyses on CpcG2-yellow fluorescent protein-histidine6, using antibody against green fluorescent protein and nickel column chromatography, confirmed the association of CpcG2 with the supercomplex. Conversely, the use of antibodies against NdhH or NdhK after blue native-polyacrylamide gel electrophoresis and in coimmunoprecipitation experiments verified the necessity of CpcG2 in stabilizing the supercomplex. Furthermore, deletion of CpcG2 destabilized NDH-1L as well as its degradation product NDH-1M and significantly decreased the number of functional PSI centers, consistent with the involvement of CpcG2 in NDH-1-dependent cyclic electron transport. The CpcG2 deletion, however, had no effect on respiration. Thus, we propose that the formation of an NDH-1L-CpcG2-PSI supercomplex in cyanobacteria facilitates PSI cyclic electron transport via NDH-1L.
College of Life and Environment Sciences, Shanghai Normal University, Shanghai 200234, China (F.G., J.Z., L.C., Z.R., W.M.).|Department of Biochemistry, Molecular Plant Biology, University of Turku, FI-20520 Turku, Finland (N.B., E.-M.A.); and.|Bioscience Center, Nagoya University, Chikusa, Nagoya 464-8601, Japan (T.O.).
Fudan
0000-0002-8882-5968
F
Gao
College of Life and Environment Sciences, Shanghai Normal University, Shanghai 200234, China (F.G., J.Z., L.C., Z.R., W.M.).|Department of Biochemistry, Molecular Plant Biology, University of Turku, FI-20520 Turku, Finland (N.B., E.-M.A.); and.|Bioscience Center, Nagoya University, Chikusa, Nagoya 464-8601, Japan (T.O.).
Jiaohong
J
Zhao
College of Life and Environment Sciences, Shanghai Normal University, Shanghai 200234, China (F.G., J.Z., L.C., Z.R., W.M.).|Department of Biochemistry, Molecular Plant Biology, University of Turku, FI-20520 Turku, Finland (N.B., E.-M.A.); and.|Bioscience Center, Nagoya University, Chikusa, Nagoya 464-8601, Japan (T.O.).
Liping
L
Chen
College of Life and Environment Sciences, Shanghai Normal University, Shanghai 200234, China (F.G., J.Z., L.C., Z.R., W.M.).|Department of Biochemistry, Molecular Plant Biology, University of Turku, FI-20520 Turku, Finland (N.B., E.-M.A.); and.|Bioscience Center, Nagoya University, Chikusa, Nagoya 464-8601, Japan (T.O.).
Natalia
0000-0001-5176-3639
N
Battchikova
College of Life and Environment Sciences, Shanghai Normal University, Shanghai 200234, China (F.G., J.Z., L.C., Z.R., W.M.).|Department of Biochemistry, Molecular Plant Biology, University of Turku, FI-20520 Turku, Finland (N.B., E.-M.A.); and.|Bioscience Center, Nagoya University, Chikusa, Nagoya 464-8601, Japan (T.O.).
Zhaoxing
Z
Ran
College of Life and Environment Sciences, Shanghai Normal University, Shanghai 200234, China (F.G., J.Z., L.C., Z.R., W.M.).|Department of Biochemistry, Molecular Plant Biology, University of Turku, FI-20520 Turku, Finland (N.B., E.-M.A.); and.|Bioscience Center, Nagoya University, Chikusa, Nagoya 464-8601, Japan (T.O.).
Eva-Mari
0000-0002-2922-1435
EM
Aro
College of Life and Environment Sciences, Shanghai Normal University, Shanghai 200234, China (F.G., J.Z., L.C., Z.R., W.M.).|Department of Biochemistry, Molecular Plant Biology, University of Turku, FI-20520 Turku, Finland (N.B., E.-M.A.); and.|Bioscience Center, Nagoya University, Chikusa, Nagoya 464-8601, Japan (T.O.).
Teruo
0000-0001-6061-8273
T
Ogawa
College of Life and Environment Sciences, Shanghai Normal University, Shanghai 200234, China (F.G., J.Z., L.C., Z.R., W.M.); wma@shnu.edu.cn.|Department of Biochemistry, Molecular Plant Biology, University of Turku, FI-20520 Turku, Finland (N.B., E.-M.A.); and wma@shnu.edu.cn.|Bioscience Center, Nagoya University, Chikusa, Nagoya 464-8601, Japan (T.O.) wma@shnu.edu.cn.
Weimin
0000-0003-4964-415X
W
Ma
D000332:Aerobiosis; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D004251:DNA Transposable Elements / Q000235:genetics; D004579:Electron Transport; D017353:Gene Deletion; D008954:Models, Biological; D046912:Multiprotein Complexes / Q000378:metabolism*; D009154:Mutation / Q000235:genetics; D045331:Photosystem I Protein Complex / Q000378:metabolism; D055550:Protein Stability; D046939:Synechocystis / Q000378:metabolism*
D001426:Bacterial Proteins; D004251:DNA Transposable Elements; D046912:Multiprotein Complexes; D045331:Photosystem I Protein Complex