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1b8d
From Proteopedia
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CRYSTAL STRUCTURE OF A PHYCOUROBILIN-CONTAINING PHYCOERYTHRIN
Overview
The structure of R-phycoerythrin (R-PE) from the red alga Griffithsia, monilis was solved at 1.90-A resolution by molecular replacement, using, the atomic coordinates of cyanobacterial phycocyanin from Fremyella, diplosiphon as a model. The crystallographic R factor for the final model, is 17.5% (Rfree 22.7%) for reflections in the range 100-1.90 A. The model, consists of an (alphabeta)2 dimer with an internal noncrystallographic, dyad and a fragment of the gamma-polypeptide. The alpha-polypeptide (164, amino acid residues) has two covalently bound phycoerythrobilins at, positions alpha82 and alpha139. The beta-polypeptide (177 residues) has, two phycoerythrobilins bound to residues beta82 and beta158 and one, phycourobilin covalently attached to rings A and D at residues beta50 and, beta61, respectively. The electron density of the gamma-polypeptide is, mostly averaged out by threefold crystallographic symmetry, but a, dipeptide (Gly-Tyr) and one single Tyr could be modeled. These two, tyrosine residues of the gamma-polypeptide are in close proximity to the, phycoerythrobilins at position beta82 of two symmetry-related, beta-polypeptides and are related by the same noncrystallographic dyad as, the (alphabeta)2 dimer. Possible energy transfer pathways are discussed, briefly.
About this Structure
1B8D is a Protein complex structure of sequences from Griffithsia monilis with PEB and PUB as ligands. Full crystallographic information is available from OCA.
Reference
Crystal structure of a phycourobilin-containing phycoerythrin at 1.90-A resolution., Ritter S, Hiller RG, Wrench PM, Welte W, Diederichs K, J Struct Biol. 1999 Jun 15;126(2):86-97. PMID:10388620
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