1PSE

THE THREE-DIMENSIONAL SOLUTION STRUCTURE OF PSAE FROM THE CYANOBACTERIUM SYNECHOCOCCUS SP. STRAIN PCC 7002: A PHOTOSYSTEM I PROTEIN THAT SHOWS STRUCTURAL HOMOLOGY WITH SH3 DOMAINS

Summary for 1PSE

• Entry DOI: 10.2210/pdb1pse/pdb
• Descriptor: PHOTOSYSTEM I ACCESSORY PROTEIN E (1 entity in total)
• Functional Keywords: photosystem i
• Biological source: Synechococcus sp.
• Cellular location: Cellular thylakoid membrane; Peripheral membrane protein: P31969
• Total number of polymer chains: 1
• Total formula weight: 7545.46

Authors

Falzone, C.J.,Kao, Y.-H.,Zhao, J.,Bryant, D.A.,Lecomte, J.T.J. (deposition date: 1994-04-13, release date: 1995-04-20, Last modification date: 2024-05-01)

Primary citation

Falzone, C.J.,Kao, Y.H.,Zhao, J.,Bryant, D.A.,Lecomte, J.T.
Three-dimensional solution structure of PsaE from the cyanobacterium Synechococcus sp. strain PCC 7002, a photosystem I protein that shows structural homology with SH3 domains.
Biochemistry, 33:6052-6062, 1994

PubMed Abstract: PsaE is a 69 amino acid polypeptide from photosystem I present on the stromal side of the thylakoid membrane. The three-dimensional solution structure of this protein from the cyanobacterium Synechococcus sp. strain PCC 7002 was determined at pH 5.8 and room temperature using over 900 experimental restraints derived from two- and three-dimensional NMR experiments. The structure is comprised of a well-defined five-stranded beta-sheet with (+1, +1, +1, -4 alpha) topology. There is no helical region except for a single turn of 3(10) helix between the beta D and beta E strands. PsaE also exhibits a large unrestrained loop spanning residues 42-56. A comparison to known protein structures revealed similarity with the Src homology 3 (SH3) domain, a membrane-associated protein involved in signal transduction in eukaryotes. The match is remarkable as 47 of the alpha-carbons of PsaE can be superimposed onto those of the SH3 domain from chicken brain alpha-spectrin with a root-mean-square deviation of 2.3 A. Although the amino acid sequences have low identity and the loops are different in both proteins, the topology of the beta-sheet and the 3(10) turn is conserved. SH3 domains from other sources show a similar structural homology. The structure of PsaE was used to suggest approaches for elucidating its roles within photosystem I.

PubMed: 8193119
DOI: 10.1021/bi00186a004

Experimental method

SOLUTION NMR