1GXI

PsaE Subunit of the Photosystem I of the Cyanobacterium Synechocystis sp. PCC 6803

Summary for 1GXI

• Entry DOI: 10.2210/pdb1gxi/pdb
• Descriptor: PHOTOSYSTEM I REACTION CENTER SUBUNIT IV (1 entity in total)
• Functional Keywords: photosynthesis, photosystem i, psae sub-unit, thylakoid
• Biological source: SYNECHOCYSTIS SP.
• Cellular location: Cellular thylakoid membrane ; Peripheral membrane protein : P12975
• Total number of polymer chains: 1
• Total formula weight: 8022.89

Authors

Barth, P.,Savarin, P.,Gilquin, B.,Lagoutte, B.,Ochsenbein, F. (deposition date: 2002-04-05, release date: 2003-04-04, Last modification date: 2024-05-15)

Primary citation

Barth, P.,Savarin, P.,Gilquin, B.,Lagoutte, B.,Ochsenbein, F.
Solution NMR Structure and Backbone Dynamics of the Psae Subunit of Photosyetm I from Synechocystis Sp. Pcc 6803
Biochemistry, 41:13902-13914, 2002

PubMed Abstract: PsaE is a small peripheral subunit of photosystem I (PSI) that is very accessible to the surrounding medium. It plays an essential role in optimizing the interactions with the soluble electron acceptors of PSI, ferredoxin and flavodoxin. The solution structure of PsaE from the cyanobacterium Synechocystis sp. PCC 6803 has been investigated by NMR with a special emphasis on its protein dynamic properties. PsaE is characterized by a well-defined central core that consists of a five-stranded beta-sheet (+1, +1, +1, -4x). Four loops (designated the A-B, B-C, C-D, and D-E loops) connect these beta-strands, the overall resulting structure being that of an SH3-like domain. As compared to previously determined PsaE structures, conformational differences are observed in the first three loops. The flexibility of the loops was investigated using (15)N relaxation experiments. This flexibility is small in amplitude for the A-B and B-C loops, but is large for the C-D loop, particularly in the region corresponding to the missing sequence of Nostoc sp. PCC 8009. The plasticity of the connecting loops in the free subunit is compared to that when bound to the PSI and discussed in relation to the insertion process and the function(s) of PsaE.

PubMed: 12437347
DOI: 10.1021/BI0259599

Experimental method

SOLUTION NMR