1psf
From Proteopedia
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
Overview
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.
About this Structure
1PSF is a Single protein structure of sequence from Synechococcus sp.. Full crystallographic information is available from OCA.
Reference
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., Falzone CJ, Kao YH, Zhao J, Bryant DA, Lecomte JT, Biochemistry. 1994 May 24;33(20):6052-62. PMID:8193119 Page seeded by OCA on Sat May 3 05:26:08 2008
