1qgw

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spinqualitylabelsall models 1qgw, resolution 1.63Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

CRYSTAL STRUCTURE OF PHYCOERYTHRIN 545 FROM THE MARINE CRYPTOPHYTE RHODOMONAS CS24

Overview

Cryptophytes are unicellular photosynthetic algae that use a lumenally, located light-harvesting system, which is distinct from the phycobilisome, structure found in cyanobacteria and red algae. One of the key components, of this system is water-soluble phycoerythrin (PE) 545 whose expression is, enhanced by low light levels. The crystal structure of the heterodimeric, alpha(1)alpha(2)betabeta PE 545 from the marine cryptophyte Rhodomonas, CS24 has been determined at 1.63-A resolution. Although the beta-chain, structure is similar to the alpha and beta chains of other known, phycobiliproteins, the overall structure of PE 545 is novel with the alpha, chains forming a simple extended fold with an antiparallel beta-ribbon, followed by an alpha-helix. The two doubly linked beta50/beta61, chromophores (one on each beta subunit) are in van der Waals contact, suggesting that exciton-coupling mechanisms may alter their spectral, properties. Each alpha subunit carries a covalently linked, 15,16-dihydrobiliverdin chromophore that is likely to be the final energy, acceptor. The architecture of the heterodimer suggests that PE 545 may, dock to an acceptor protein via a deep cleft and that energy may be, transferred via this intermediary protein to the reaction center.

About this Structure

1QGW is a Protein complex structure of sequences from Rhodomonas sp. with CL, MG, DBV and PEB as ligands. Full crystallographic information is available from OCA.

Reference

Evolution of a light-harvesting protein by addition of new subunits and rearrangement of conserved elements: crystal structure of a cryptophyte phycoerythrin at 1.63-A resolution., Wilk KE, Harrop SJ, Jankova L, Edler D, Keenan G, Sharples F, Hiller RG, Curmi PM, Proc Natl Acad Sci U S A. 1999 Aug 3;96(16):8901-6. PMID:10430868

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