Showing papers on "Phycoerythrobilin published in 1993"
TL;DR: The results suggest that ectopic expression of biliverdin reductase in plants will prevent assembly of the functional photoreceptor and thus will potentially alter light-mediated plant growth and development.
111 citations
TL;DR: In terms of amino acid sequence identity RPCII is highly homologous to CPC and PEC, suggesting that the known three-dimensional structures of the latter two are representative of RPCII, and certain residues were identified among the three phycocyanins as possibly correlating with specific bilin isomers.
Abstract: R-phycocyanin II (RPCII) is a recently discovered member of the phycocyanin family of photosynthetic light-harvesting proteins. Genes encoding the α and β subunits of RPCII were cloned and sequenced from marine Synechococcus sp. strains WH8020 and WH8103. The deduced amino acid sequences of RPCII were compared to two other types of phycocyanin, C-phycocyanin (CPC) and phycoerythrocyanin (PEC). These three types vary in the composition of their covalently bound bilin prosthetic groups. In terms of amino acid sequence identity RPCII is highly homologous to CPC and PEC, suggesting that the known three-dimensional structures of the latter two are representative of RPCII. Thus the amino acid residues contacting the three bilins of RPCII could be inferred and compared to those in CPC and PEC. Certain residues were identified among the three phycocyanins as possibly correlating with specific bilin isomers. In overall sequence RPCII and CPC are more homologous to one another than either is to PEC. This probably reflects functional homology in the roles of RPCII and CPC in the transfer of light energy to the core of the phycobilisome, a function not attributed to PEC. The genomes of Synechococcus sp. strains WH8020, WH8103 and WH7803 share homologous open reading frames in the vicinity of RPCII genes. The nucleotide sequence extending 3′ from RPCII genes in strain WH8020 revealed two open reading frames homologous to components of an αCPC phycocyanobilin lyase. These open reading frames may encode a lyase specific for the attachment of phycoerythrobilin to αRPCII.
21 citations
TL;DR: R-Phycoerythrin was purified from two species of red algae and suggested the well-known (αβ)6γ molecular structure.
Abstract: R-Phycoerythrin was purified from two species of red algae: Callithamnion corymbosum from the Black Sea and Antithamnion sparsum from the Sea of Japan. Three polypeptide γ-subunits differing slightly in molecular weight (31.6, 30.8 and 29.0 kDa) in a 1:5:2 stoichiometry were found in R-phycoerythrin from C. corymbosum by reverse-phase chromatography on a fast performance liquid chromatography (FPLC) system. The ratio of the total number of γ1-, γ2- and γ3-subunits to the total number of α- and β-subunits of R-phycoerythrin was 1:12 and suggested the well-known (αβ)6γ molecular structure. The chromophore contents of the γ-subunits were identical: three phycourobilins and two phycoerythrobilins. R-Phycoerythrin from A. sparsum also contained three γ-subunits but with different chromophore compositions: one carried three phycourobilins and two phycoerythrobilins while the other carried four phycourobilins and one phycoerythrobilin. The chromophore composition of the third γ-subunit remained unclarified.
13 citations