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Structure of a monomeric photosystem I core associated with iron-stress-induced-A proteins from Anabaena sp. PCC 7120.
- Source :
- Nature Communications; 2/17/2023, Vol. 14 Issue 1, p1-13, 13p
- Publication Year :
- 2023
-
Abstract
- Iron-stress-induced-A proteins (IsiAs) are expressed in cyanobacteria under iron-deficient conditions. The cyanobacterium Anabaena sp. PCC 7120 has four isiA genes; however, their binding property and functional roles in PSI are still missing. We analyzed a cryo-electron microscopy structure of a PSI-IsiA supercomplex isolated from Anabaena grown under an iron-deficient condition. The PSI-IsiA structure contains six IsiA subunits associated with the PsaA side of a PSI core monomer. Three of the six IsiA subunits were identified as IsiA1 and IsiA2. The PSI-IsiA structure lacks a PsaL subunit; instead, a C-terminal domain of IsiA2 occupies the position of PsaL, which inhibits the oligomerization of PSI, leading to the formation of a PSI monomer. Furthermore, excitation-energy transfer from IsiAs to PSI appeared with a time constant of 55 ps. These findings provide insights into both the molecular assembly of the Anabaena IsiA family and the functional roles of IsiAs. IsiAs are unique light-harvesting complexes in cyanobacteria. Here, authors solved the structure of a PSI monomer associated with six IsiAs from Anabaena by cryo-EM, which provide insights into molecular diversity and functions of different IsiAs. [ABSTRACT FROM AUTHOR]
- Subjects :
- ANABAENA
FAMILY roles
PROTEINS
SYNECHOCOCCUS
MONOMERS
OLIGOMERIZATION
Subjects
Details
- Language :
- English
- ISSN :
- 20411723
- Volume :
- 14
- Issue :
- 1
- Database :
- Complementary Index
- Journal :
- Nature Communications
- Publication Type :
- Academic Journal
- Accession number :
- 161963644
- Full Text :
- https://doi.org/10.1038/s41467-023-36504-1