2c9e

Peridinin-chlorophyll a protein, high-salt form

spinqualitylabelsall models 2c9e, resolution 2.10Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2c9e is a 1 chain structure with sequence from Amphidinium carterae. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.1Å Ligands: CLA, DGD, MG, PID Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function O76183_AMPCA 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 Light-harvesting complexes have evolved into very different structures but fulfill the same function, efficient harvesting of solar energy. In these complexes, pigments are fine-tuned and properly arranged to gather incoming photons. In the photosynthetic dinoflagellate Amphidinium carterae, two variants of the soluble light-harvesting complex PCP have been found [main form PCP (MFPCP) and high-salt PCP (HSPCP)], which show small variations in their pigment arrangement and tuning mechanisms. This feature makes them ideal models for studying pigment-protein interactions. Here we present the X-ray structure of the monomeric HSPCP determined at 2.1 A resolution and compare it to the structure of trimeric MFPCP. Despite the high degree of structural similarity (rmsd C(alpha)-C(alpha) of 1.89 A), the sequence variations lead to a changed overall pigment composition which includes the loss of two carotenoid molecules and a dramatic rearrangement of the chlorophyll phytol chains and of internal lipid molecules. On the basis of a detailed structural comparison, we favor a macrocycle geometry distortion of the chlorophylls rather than an electrostatic effect to explain energetic splitting of the chlorophyll a Q(y) bands [Ilagan, R. P. (2006) Biochemistry 45, 14052-14063]. Our analysis supports their assignment of peridinin 611* as the single blue-shifted peridinin in HSPCP but also highlights another electrostatic feature due to glutamate 202 which could add to the observed binding site asymmetry of the 611*/621* peridinin pair. X-ray Structure of the High-Salt Form of the Peridinin-Chlorophyll a-Protein from the Dinoflagellate Amphidinium carterae: Modulation of the Spectral Properties of Pigments by the Protein Environment.,Schulte T, Sharples FP, Hiller RG, Hofmann E Biochemistry. 2009 Apr 27. PMID:19371099 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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