TY - JOUR
T1 - Non-conventional octameric structure of C-phycocyanin
AU - Minato, Takuo
AU - Teramoto, Takamasa
AU - Adachi, Naruhiko
AU - Hung, Nguyen Khac
AU - Yamada, Kaho
AU - Kawasaki, Masato
AU - Akutsu, Masato
AU - Moriya, Toshio
AU - Senda, Toshiya
AU - Ogo, Seiji
AU - Kakuta, Yoshimitsu
AU - Yoon, Ki Seok
N1 - Funding Information:
Thermoleptolyngbya sp. O-77 was named after Saori Ogo, whose assistance was invaluable to the hunt for a new thermophilic cyanobacterium. This paper is dedicated to her memory. This work was supported in part by JST CREST Grant Number JPMJCR18R2 (S.O.), JSPS KAKENHI Grant Numbers JP18H02091 (K.-S.Y) and JP18J00191 (T. Minato), MEXT Leading Initiative for Excellent Young Researchers Grant Number JPMXS0320200400 (T. Minato), JSPS Core-to-Core Program, the World Premier International Research Center Initiative (WPI), Japan, and the Platform Project for Supporting Drug Discovery and Life Science Research (Basis for Supporting Innovative Drug Discovery and Life Science Research (BINDS)) from the Japan Agency for Medical Research and Development (AMED) under Grant Number JP21am0101071 (supporting no. 2493). T. Minato was supported by the JSPS through a Research Fellowship for Young Scientists. We thank the staff members of the beamline BL45XU facilities at SPring-8 for their help with X-ray data collections. The cryo-EM data were collected at the Cryo-EM facility in KEK (Ibaraki, Japan).
Publisher Copyright:
© 2021, The Author(s).
PY - 2021/12
Y1 - 2021/12
N2 - C-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.
AB - C-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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U2 - 10.1038/s42003-021-02767-x
DO - 10.1038/s42003-021-02767-x
M3 - Article
C2 - 34716405
AN - SCOPUS:85118470403
SN - 2399-3642
VL - 4
JO - Communications Biology
JF - Communications Biology
IS - 1
M1 - 1238
ER -