Thomas J C, Passaquet C
Laboratoire de Photorégulation et Dynamique des Membranes Végétales, CNRS, Unité de Recherche Associée 1810, GDR 1002, Ecole Normale Supérieure, 46 rue d'Ulm, 75 230 Paris Cedex 05, France.
J Biol Chem. 1999 Jan 22;274(4):2472-82. doi: 10.1074/jbc.274.4.2472.
We describe here the spectral and biochemical properties of a novel biliprotein belonging to the phycoerythrin family, purified from the phycobilisome of a unicellular red alga, Rhodella reticulata strain R6. This biliprotein is assembled from a unique beta-type subunit, chloroplast-encoded, whose hexameric or dodecameric aggregates are stabilized by unusually large linkers (87 and 60 kDa) encoded by the nuclear genome. Although each beta-type subunit bears two phycoerythrobilins and one phycocyanobilin per chain, the linker polypeptides are non-chromophorylated. The apoprotein of the beta-subunit of the R. reticulata R6 phycoerythrin is specified by a monocistronic rpeB chloroplast gene that is split into three exons. We discuss the relationships between R6 beta-phycoerythrin and the previously published polypeptide sequences, the structural consequences due to the absence of an alpha-subunit, and its evolutionary implications.
我们在此描述了一种从单细胞红藻网状红皮藻（Rhodella reticulata）菌株R6的藻胆体中纯化得到的、属于藻红蛋白家族的新型双蛋白的光谱和生化特性。这种双蛋白由一个独特的β型亚基组装而成，该亚基由叶绿体编码，其六聚体或十二聚体聚集体通过核基因组编码的异常大的连接子（87和60 kDa）得以稳定。尽管每个β型亚基每条链带有两个藻红胆素和一个藻蓝胆素，但连接子多肽未被发色团化。网状红皮藻R6藻红蛋白β亚基的脱辅基蛋白由一个单顺反子的叶绿体rpeB基因指定，该基因被分成三个外显子。我们讨论了R6β-藻红蛋白与先前发表的多肽序列之间的关系、由于缺乏α亚基而导致的结构后果及其进化意义。
