EC Number |
Subunits |
Reference |
---|
1.97.1.12 | ? |
21000-22000 Da, photosystem 1 subunit PsaF that is involved in the docking of the electron-donor proteins plastocyanin and cytochrome c6, SDS-PAGE |
713465 |
1.97.1.12 | dimer |
in strain TS-821 PSI forms tetrameric, dimeric, and monomeric species, a tetrameric PSI has two PSI dimers associated together with interdimer gaps, while the PSI dimer is composed of two tightly tethered PSI monomers, subunit organization, structure comparisons, overview |
746026 |
1.97.1.12 | heterotetramer |
two-dimensional maps obtained by single particle electron microscopy clearly show that the tetramer lacks four-fold symmetry and is actually composed of a dimer of dimers with C2 symmetry, cryo-electron microscopy is used for 3D reconstruction of the PSI tetramer complex and a 3D model at 11.5 A resolution is obtained. A 2D map within the membrane plane of about 6.1 A is used for modeling, structure model comparison with the PSI structure of Thermosynechococcus elongatus at 2.5 A, PDB ID 1JB0, overview. The PsaL subunit of strain TS-821 is modeled using PsaL subunit of Pisum sativum as a template, PDB ID 4Y28L. The modeled PsaL subunit of TS-821 is used to substitute the existing PsaL subunit in crystal structure of Thermosynechococcus elongatus and most of the subunits from the crystal structure of Thermosynechococcus elongatus are fitted separately into the 3D volumemap of TS-821. Comparison of trimeric interface of Thermosynechococcus elongatus with interface type 1 of TS-821 |
744411 |
1.97.1.12 | monomer |
in strain TS-821 PSI forms tetrameric, dimeric, and monomeric species, a tetrameric PSI has two PSI dimers associated together with interdimer gaps, while the PSI dimer is composed of two tightly tethered PSI monomers, subunit organization, structure comparisons, overview |
746026 |
1.97.1.12 | monomer |
inside the trimer, subunits PsaL, PsaI and PsaM (5 alpha-helices in total) are located in the center of the trimerization domain of PSI, thereby forming most of the contacts between the monomers |
746500 |
1.97.1.12 | More |
a cyanobacterial PSI monomer consists of 1112 protein subunits |
710876 |
1.97.1.12 | More |
amino acid sequence comparisons |
744411 |
1.97.1.12 | More |
plant and algal PSI complexes contain 14-15 protein subunits. Of these, only PsaA, PsaB, and PsaC bind the cofactors of the electron transfer system. PsaA and PsaB form the core complex around which other subunits are organized. The PsaC, PsaD, PsaH, and PsaE proteins form the stromal peripheral domain that contains the terminal electron donors and the ferredoxin-docking site. PsaN of plant and algal PSI is a lumenal peripheral protein. PsaN and the large lumenal domain of PsaF form the plastocyanin docking site of plant and algal PSI. The remaining proteins of PSI are integral membrane proteins with 13 transmembrane helices. The function of the PSI proteins |
710876 |
1.97.1.12 | More |
PsaE (a peripheral subunit of the PSI complex) is involved in the docking of ferredoxin/flavodoxin to the PSI complex and also participates in the cyclic electron transfer around phosphosystem I. The interactions formed between different subunits of the complex may be hydrophobic or electrostatic in nature |
711194 |
1.97.1.12 | More |
the crystal structure reveals the configuration of PsaK, a core subunit important for state transitions in plants, a conserved network of water molecules surrounding the electron transfer centres and an elaborate structure of lipids bridging PSI and its LHCI antenna. The structure of Psak suggests alternative conformations, overview |
745870 |