Capuano V, Thomas J C, Tandeau de Marsac N, Houmard J
Unité de Physiologie Microbienne Centre National de la Rechercke Scientifique (CNRS URA 1129), Institut Pasteur, Paris, France.
J Biol Chem. 1993 Apr 15;268(11):8277-83.
In cyanobacteria, phycobilisomes are regularly arrayed on the surface of the photosynthetic membranes, and their role is to funnel light energy to the underlying photosystem II reaction center. A model has recently been proposed that ascribes to the so-called LCM, a central role in the building up of the phycobilisome, in addition to its role of terminal energy acceptor (Capuano, V., Braux, A.-S., Tandeau de Marsac, N., and Houmard, J. (1991) J. Biol. Chem. 266, 7239-7247). The phycobilisomes of Calothrix sp. PCC 7601 are typically of the type found in most cyanobacteria. Those of Synechococcus PCC 7942 (or PCC 6301) differ in having central cores made up of two instead of three cylinders. We have integrated the Calothrix PCC 7601 apcE gene that encodes the LCM into the chromosome of a Synechococcus PCC 7942 strain. We have observed that the heterologous gene is expressed and that the corresponding product carries a bilin-type chromophore and can be detected in the phycobilisome fraction of the Synechococcus strain. Moreover, it is shown that, in agreement with our model, this LCM can direct the formation of phycobilisomes that have three-cylinder cores.
在蓝细菌中，藻胆体规则地排列在光合膜表面，其作用是将光能导向下方的光系统II反应中心。最近有人提出一种模型，认为所谓的LCM除了作为末端能量受体的作用外，在藻胆体的构建中也起着核心作用（卡普阿诺，V.，布劳克斯，A.-S.，坦德奥·德·马尔萨克，N.，和胡马尔德，J.（1991年）《生物化学杂志》266，7239 - 7247）。眉藻属PCC 7601的藻胆体通常是大多数蓝细菌中发现的那种类型。聚球藻PCC 7942（或PCC 6301）的藻胆体不同之处在于其中心核由两个而非三个圆柱体组成。我们已将编码LCM的眉藻属PCC 7601 apcE基因整合到聚球藻PCC 7942菌株的染色体中。我们观察到该异源基因得以表达，并且相应产物带有一个胆素型发色团，可在聚球藻菌株的藻胆体组分中检测到。此外，结果表明，与我们的模型一致，这种LCM能够指导具有三个圆柱体核心的藻胆体的形成。
