Characterization of the Different Peripheral Light-Harvesting Complexes from High- and Low-Light Grown Cells fromRhodopseudomonas palustris†

Biochemistry ◽  
1999 ◽  
Vol 38 (16) ◽  
pp. 5185-5190 ◽  
Author(s):  
Andrew Gall ◽  
Bruno Robert
2009 ◽  
Vol 97 (11) ◽  
pp. 3019-3028 ◽  
Author(s):  
Vladimíra Moulisová ◽  
Larry Luer ◽  
Sajjad Hoseinkhani ◽  
Tatas H.P. Brotosudarmo ◽  
Aaron M. Collins ◽  
...  

2011 ◽  
Vol 440 (1) ◽  
pp. 51-61 ◽  
Author(s):  
Tatas H. P. Brotosudarmo ◽  
Aaron M. Collins ◽  
Andrew Gall ◽  
Aleksander W. Roszak ◽  
Alastair T. Gardiner ◽  
...  

The differing composition of LH2 (peripheral light-harvesting) complexes present in Rhodopseudomonas palustris 2.1.6 have been investigated when cells are grown under progressively decreasing light intensity. Detailed analysis of their absorption spectra reveals that there must be more than two types of LH2 complexes present. Purified HL (high-light) and LL (low-light) LH2 complexes have mixed apoprotein compositions. The HL complexes contain PucABa and PucABb apoproteins. The LL complexes contain PucABa, PucABd and PucBb-only apoproteins. This mixed apoprotein composition can explain their resonance Raman spectra. Crystallographic studies and molecular sieve chromatography suggest that both the HL and the LL complexes are nonameric. Furthermore, the electron-density maps do not support the existence of an additional Bchl (bacteriochlorophyll) molecule; rather the density is attributed to the N-termini of the α-polypeptide.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Takuo Minato ◽  
Takamasa Teramoto ◽  
Naruhiko Adachi ◽  
Nguyen Khac Hung ◽  
Kaho Yamada ◽  
...  

AbstractC-phycocyanin (CPC), a blue pigment protein, is an indispensable component of giant phycobilisomes, which are light-harvesting antenna complexes in cyanobacteria that transfer energy efficiently to photosystems I and II. X-ray crystallographic and electron microscopy (EM) analyses have revealed the structure of CPC to be a closed toroidal hexamer by assembling two trimers. In this study, the structural characterization of non-conventional octameric CPC is reported for the first time. Analyses of the crystal and cryogenic EM structures of the native CPC from filamentous thermophilic cyanobacterium Thermoleptolyngbya sp. O–77 unexpectedly illustrated the coexistence of conventional hexamer and novel octamer. In addition, an unusual dimeric state, observed via analytical ultracentrifugation, was postulated to be a key intermediate structure in the assemble of the previously unobserved octamer. These observations provide new insights into the assembly processes of CPCs and the mechanism of energy transfer in the light-harvesting complexes.


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