1b8d: Difference between revisions

[[Image:1b8d.gif|left|200px]]<br /><applet load="1b8d" size="350" color="white" frame="true" align="right" spinBox="true"  

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.

1B8D is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Griffithsia_monilis Griffithsia monilis] with <scene name='pdbligand=PEB:'>PEB</scene> and <scene name='pdbligand=PUB:'>PUB</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1B8D OCA].  

[[Category: Hiller, R G.]]

[[Category: Wrench, P M.]]

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