2c7k

From Proteopedia

Laue structure of phycoerythrocyanin from Mastigocladus laminosus

PDB ID 2c7k

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Structural highlights

2c7k is a 2 chain structure with sequence from Mastigocladus laminosus. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:	X-ray diffraction, Resolution 3.2Å
Ligands:	,
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

PHEA_MASLA Light-harvesting photosynthetic bile pigment-protein from the phycobiliprotein complex.

Evolutionary Conservation

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

Publication Abstract from PubMed

Phycoerythrocyanin is the only cyanobacterial phycobiliprotein containing phycoviolobilin as a chromophore. The phycoviolobilin chromophore is photo-reactive; upon irradiation, the chromophore undergoes a Z/E-isomerization involving the rotation of pyrrole-ring D. We have determined the structure of trimeric phycoerythrocyanin at three different experimental settings: monochromatically at 110 K and 295 K as well as with the Laue method at 288 K. Based on their chemical structures, the restraints for the phycoviolobilin of the alpha-subunit and for the phycocyanobilin chromophores of the beta-subunit were newly generated, which allows a chemically meaningful refinement of both chromophores. All three phycoerythrocyanin structures are very similar; the subunits match within 0.5 A. The detailed comparison of the data obtained with the different measurements provided information about the protein properties around the phycoviolobilin chromophore. For the first time, crystals of a phycobilisome protein are used successfully with the Laue technique. This paves the way for time-resolved macromolecular crystallography, which is able to elucidate the exact mechanisms of the phycoviolobilin photoactivity including the protein involvement.

Local protein flexibility as a prerequisite for reversible chromophore isomerization in alpha-phycoerythrocyanin.,Schmidt M, Krasselt A, Reuter W Biochim Biophys Acta. 2006 Jan;1764(1):55-62. Epub 2005 Nov 21. PMID:16377266^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Schmidt M, Krasselt A, Reuter W. Local protein flexibility as a prerequisite for reversible chromophore isomerization in alpha-phycoerythrocyanin. Biochim Biophys Acta. 2006 Jan;1764(1):55-62. Epub 2005 Nov 21. PMID:16377266 doi:10.1016/j.bbapap.2005.10.022