1KTP

Crystal structure of c-phycocyanin of synechococcus vulcanus at 1.6 angstroms

Summary for 1KTP

• Entry DOI: 10.2210/pdb1ktp/pdb
• Related: 1I7Y
• Descriptor: C-PHYCOCYANIN ALPHA SUBUNIT, C-PHYCOCYANIN BETA SUBUNIT, PHYCOCYANOBILIN, ... (4 entities in total)
• Functional Keywords: cyanobacteria, photosynthesis, photosystem ii, light harvesting proteins, thermostability
• Biological source: Thermosynechococcus vulcanus; More
• Cellular location: Cellular thylakoid membrane; Peripheral membrane protein; Cytoplasmic side (By similarity): P50032 P50033
• Total number of polymer chains: 2
• Total formula weight: 37453.39

Authors

Adir, N.,Dobrovetsky, E.,Lerner, N. (deposition date: 2002-01-17, release date: 2002-03-06, Last modification date: 2025-03-12)

Primary citation

Adir, N.,Vainer, R.,Lerner, N.
Refined structure of c-phycocyanin from the cyanobacterium Synechococcus vulcanus at 1.6 A: insights into the role of solvent molecules in thermal stability and co-factor structure
Biochim.Biophys.Acta, 1556:168-174, 2002

PubMed Abstract: The crystal structure of the light-harvesting phycobiliprotein, c-phycocyanin from the thermophilic cyanobacterium Synechococcus vulcanus has been refined to 1.6 A resolution based on the previously determined lower resolution structure (PDB entry 1I7Y). The improved data was collected using synchrotron radiation at 100 K. The significantly improved crystallographic data has lead to improved calculated electron density maps, allowing the unambiguous positioning of all protein and co-factor atoms and the positioning of 377 solvent molecules. The positions of solvent molecules at specific sites important for stabilization of different levels of self-assembly of the phycobilisome structure were identified and the bonding network is described. The presence of solvent molecules in the vicinity of the co-factors and in intermolecular spaces is identified and their possible roles are suggested. All three of the phycocyanobilin co-factors bind water molecules at specific sites between the propionic acid side chains. Molecular dynamic (MD) simulations support that these special waters have a role in stabilization of this conformation. On the basis of the crystal packing reported here and in comparison to other phycobiliprotein crystal forms, we have analyzed the roles of specific sites on the formation of the phycobilisome complex.

PubMed: 12460674
DOI: 10.1016/S0005-2728(02)00359-6

Experimental method

X-RAY DIFFRACTION (1.6 Å)