Significant energy transfer from CpcG2-phycobilisomes to photosystem I in the cyanobacterium Synechococcus sp. PCC 7002 in the absence of ApcD-dependent state transitions.
Hemidiscoidal phycobilisomes (PBS), the major light harvesting complexes of photosynthesis in most cyanobacteria, are composed of rods and cores, which are linked by the linker CpcG1 (L(RC)). Another type of PBS, CpcG2-PBS exits and their function in energy transfer has not been fully understood. We measured growth rates, absorption cross-sections and quantum efficiency of photosystem I in mutant strains of Synechococcus PCC sp. 7002 lacking the linker CpcG2. Our results showed that energy transfer from CpcG2-PBS to PSI in the absence of state transitions could be significant under PBS-absorbing light and energy transfer from two types of PBS is independent to each other. Evidence also suggested that CpcG2 anchors the CpcG2-PBS to thylakoid membranes.
State Key Laboratory of Protein and Plant Genetic Engineering, College of Life Sciences, Peking University, Beijing 100871, China.
Guoping
G
Deng
Fei
F
Liu
Xianwei
X
Liu
Jindong
J
Zhao
D000042:Absorption; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000502:physiology; D002734:Chlorophyll / Q000737:chemistry; D000458:Cyanobacteria / Q000378:metabolism*; D005288:Ferredoxins / Q000737:chemistry; D005786:Gene Expression Regulation; D049452:Green Fluorescent Proteins / Q000378:metabolism; D009154:Mutation; D017785:Photons; D010788:Photosynthesis; D045331:Photosystem I Protein Complex / Q000737:chemistry*; D045524:Phycobilisomes / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics* / Q000502:physiology; D013050:Spectrometry, Fluorescence / Q000379:methods; D046940:Synechococcus / Q000378:metabolism*; D020524:Thylakoids / Q000378:metabolism; D013997:Time Factors
D029681:Arabidopsis Proteins; D005288:Ferredoxins; D045331:Photosystem I Protein Complex; D045524:Phycobilisomes; D010940:Plant Proteins; D002734:Chlorophyll; D049452:Green Fluorescent Proteins