2bv8

Publication Abstract from PubMed

Phycocyanin is a phycobiliprotein involved in light harvesting and conduction of light to the reaction centers in cyanobacteria and red algae. The structure of C-phycocyanin from Gracilaria chilensis was solved by X-ray crystallography at 2.0 A resolution in space group P2(1). An interaction model between two PC heterohexamers was built, followed by molecular dynamic refinement. The best model showed an inter-hexamer rotation of 23 degrees . The coordinates of a PC heterohexamer (alphabeta)(6) and of the PC-PC complex were used to perform energy transfer calculations between chromophores pairs using the fluorescence resonance energy transfer approach (FRET). Two main intra PC ((I)beta(3)(82)-->(I)alpha(1)(84)-->(I)alpha(5)(84)-->(I)beta(6)(82) and (I)beta(3)(153)-->(I)beta(5)(153)) and two main inter PC ((I)beta(6)(82)-->(II)beta(3)(82) and (I)beta(5)(153)-->(II)beta(3)(153)) pathways were proposed based on the values of the energy transfer constants calculated for all the chromophore pairs in the hexamer and in the complex.

The structure at 2 A resolution of Phycocyanin from Gracilaria chilensis and the energy transfer network in a PC-PC complex.,Contreras-Martel C, Matamala A, Bruna C, Poo-Caamano G, Almonacid D, Figueroa M, Martinez-Oyanedel J, Bunster M Biophys Chem. 2007 Feb;125(2-3):388-96. Epub 2006 Nov 10. PMID:17118524^[1]

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