Crystal Structure of a Light-Harvesting Protein C-Phycocyanin from Spirulina platensis

Padyana, Anil K and Bhat, Vadiraja B and Madyastha, KM and Rajashankar, KR and Ramakumar, S (2001) Crystal Structure of a Light-Harvesting Protein C-Phycocyanin from Spirulina platensis. In: Biochemical and Biophysical Research Communications, 282 (4). pp. 893-898.

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Abstract

The crystal structure of C-phycocyanin, a light-harvesting phycobiliprotein from cyanobacteria (blue-green algae) Spirulina platensis has been solved by molecular replacement technique. The crystals belong to space group $P2_1$ with cell parameters a = 107.20, b = 115.40, c = 183.04 \AA; $\beta=90.2^o$. The structure has been refined to a crystallographic R factor of 19.2% $(R_{free}=23.9$%) using the X-ray diffraction data extending up to 2.2 \AA resolution. The asymmetric unit of the crystal cell consists of two $(\alpha \beta)_6$-hexamers, each hexamer being the functional unit in the native antenna rod of cyanobacteria. The molecular structure resembles that of other reported C-phycocyanins. However, the unique form of aggregation of two $(\alpha \beta)_6$-hexamers in the crystal asymmetric unit, suggests additional pathways of energy transfer in lateral direction between the adjacent hexamers involving $\beta 155$ phycocyanobilin chromophores.

Item Type:	Journal Article
Additional Information:	Copyright of this article belongs to Academic Press.
Keywords:	Crystal structure;C-phycocyanin;Light-harvesting;Phycobiliprotein;Bilin;Chromophore;Spirulina platensis
Department/Centre:	Division of Information Sciences > BioInformatics Centre Division of Chemical Sciences > Organic Chemistry Division of Physical & Mathematical Sciences > Physics
Date Deposited:	16 Oct 2007
Last Modified:	19 Sep 2010 04:40
URI:	http://eprints.iisc.ernet.in/id/eprint/12253

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