1CPC

ISOLATION, CRYSTALLIZATION, CRYSTAL STRUCTURE ANALYSIS AND REFINEMENT OF CONSTITUTIVE C-PHYCOCYANIN FROM THE CHROMATICALLY ADAPTING CYANOBACTERIUM FREMYELLA DIPLOSIPHON AT 1.66 ANGSTROMS RESOLUTION

Summary for 1CPC

• Entry DOI: 10.2210/pdb1cpc/pdb
• Descriptor: C-PHYCOCYANIN (ALPHA SUBUNIT), C-PHYCOCYANIN (BETA SUBUNIT), PHYCOCYANOBILIN, ... (4 entities in total)
• Functional Keywords: light harvesting protein
• Biological source: Fremyella diplosiphon; More
• Cellular location: Cellular thylakoid membrane; Peripheral membrane protein; Cytoplasmic side: P07122 P07119
• Total number of polymer chains: 4
• Total formula weight: 73919.46

Authors

Duerring, M.,Schmidt, G.B.,Huber, R. (deposition date: 1990-10-11, release date: 1993-01-15, Last modification date: 2024-06-05)

Primary citation

Duerring, M.,Schmidt, G.B.,Huber, R.
Isolation, crystallization, crystal structure analysis and refinement of constitutive C-phycocyanin from the chromatically adapting cyanobacterium Fremyella diplosiphon at 1.66 A resolution.
J.Mol.Biol., 217:577-592, 1991

PubMed Abstract: Constitutive phycocyanin from cyanobacterium Fremyella diplosiphon (Calothrix sp. PCC 7601) grown in green light, has been isolated and crystallized. The crystals belong to the space group R3 with cell constants a = b = 180.26 A, c = 61.24 A, alpha = beta = 90 degrees, gamma = 120 degrees. The crystal structure has been determined by Patterson search techniques using the molecular model of C-phycocyanin from the cyanobacterium Agmenellum quadruplicatum. The asymmetric unit of the crystal cell consists of two (alpha beta)-monomers related by a local dyad. Three asymmetric units are arranged around a crystallographic triad and form an (alpha beta)6-hexamer, the functional unit in the native antenna rod. The initial structure has been refined in a cyclic manner by energy-restrained crystallographic refinement and modelling until the conventional crystallographic R-factor converged at 18.1% with data to a resolution of 1.66 A. The molecular structure resembles closely the C-phycocyanins of Mastigocladus laminosus and A. quadruplicatum. The conformation and configuration of the alpha-84 and beta-84 chromophores is very similar to the corresponding chromophores in the trimeric C-phycocyanin of M. laminosus, whereas the beta-155 chromophore differs in configuration with C(4)-Z, C(10)-Z and C(15)-Z compared to C(4)-Z, C(10)-Z, C(15)-Z,E. The stereochemistry of the beta-155 chiral centres is C(2)-RC(3)-R and C(31)-S, respectively, whereas alpha-84 and beta-84 have C(2)-RC(3)-R and C(31)-R. The amino acid sequences of constitutive and inducible phycocyanin differ mainly in residues located on the surface of the beta-subunits that mediate the inter-hexameric contacts.

PubMed: 1899708
DOI: 10.1016/0022-2836(91)90759-Y

Experimental method

X-RAY DIFFRACTION (1.66 Å)