Structural and compositional analyses of the phycobilisomes of Synechococcus sp. PCC 7002. Analyses of the wild-type strain and a phycocyanin-less mutant constructed by interposon mutagenesis |
| |
Authors: | Donald A. Bryant Robert de Lorimier Gerard Guglielmi S. Edward Stevens Jr |
| |
Affiliation: | (1) Department of Molecular and Cell Biology, The Pennsylvania State University, 16802 University Park, PA, USA;(2) Present address: Department of Microbiology and Immunology, Univeristy of California, 94720 Berkeley, CA, USA;(3) Present address: Institut Pasteur, 25-28 rue du Dr. Roux, F-75724 Paris Cedex 15, France;(4) Present address: Department of Biological Sciences, Memphis State University, 38152 Memphis, TN, USA |
| |
Abstract: | The phycobilisomes and phycobiliproteins of Synechococcus sp. PCC 7002 wild-type strain PR6000 have been isolated and characterized. The hemidiscoidal phycobilisomes of strain PR6000 are composed of eleven different polypeptides: phycocyanin and subunits; allophycocyanin and subunits; subunit of allophycocyanin B; the allophycocyanin -subunit-like polypeptide of Mr 18 000; the linker phycobiliprotein of Mr 99 000; and non-chromophore-carrying linker polypeptides of Mr 33 000, 29 000, 9000, and 8000. Several of these polypeptides were purified to homogeneity and their amino acid compositions and amino-terminal amino acid sequences were determined. Analyses of the phycobiliproteins of Synechococcus sp. PCC 7002 were greatly facilitated by comparative studies performed with a mutant strain, PR6008, constructed to be devoid of the phycocyanin and subunits by recombinant DNA techniques and transformation of strain PR6000. The absence of phycocyanin did not greatly affect the allophycocyanin content of the mutant strain but caused the doubling time to increase 2–7-fold depending upon the light intensity at which the cells were grown. Although intact phycobilisome cores could not be isolated from this mutant, it is probable that functionally intact cores do exist in vivo.Abbreviations used SDS-PAGE polyacrylamide gel electrophoresis in the presence of sodium dodecylsulfate - 2D-PAGE two-dimensional gel electrophoresis in which the first dimension consisted of isoelectric focusing in the presence of 8.0 M urea in the pH range 4–6 and the second dimension consisted of electrophoresis in the presence of sodium dodecylsulfate. The nomenclature employed for the phycobiliprotein subunits and linker polypeptides is that defined by Glazer (1985) |
| |
Keywords: | Phycobilisomes Phycobiliproteins Cyanobacterium Synechococcus sp. PCC 7002 Interposon mutagenesis |
本文献已被 SpringerLink 等数据库收录! |
|