MOLECULAR CHARACTERIZATION OF THE TERMINAL ENERGY ACCEPTOR OF CYANOBACTERIAL PHYCOBILISOMES
MOLECULAR CHARACTERIZATION OF THE TERMINAL ENERGY ACCEPTOR OF CYANOBACTERIAL PHYCOBILISOMES
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DOI：
10.1073/pnas.87.6.2152
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发表时间：
1990-03-01
影响因子：
11.1
通讯作者：
DEMARSAC, NT
中科院分区：
文献类型：
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作者：
HOUMARD, J;CAPUANO, V;DEMARSAC, NT
蓝藻通过多分子结构，藻胆体，调节排列在光合膜表面的光能。藻胆体由中心核组成，杆状体从中心核辐射。一个大的多肽（LCM，75-120 kDa）被假定作为终端能量受体和作为连接多肽，稳定藻胆体结构。我们在这里报告的基因（apcE），编码这种LCM多肽在眉藻属PCC 7601的表征。它位于编码藻胆体核心（别藻蓝蛋白）主要成分的基因上游，是同一操纵子的一部分。推导的氨基酸序列表明，LCM的N-末端区域与其他藻胆蛋白亚基的同源性，从而构成了色蛋白结构域。该分子的另一部分由四个重复结构域组成，其与藻蓝蛋白杆接头多肽的N-末端区域高度同源。 LCM的不同结构域的预测的二级结构进行了讨论，这种大分子的不同作用和性质。
Cyanobacteria harvest light energy through multimolecular structures, the phycobilisomes, regulatory arrayed at the surface of the photosynthetic membranes. Phycobilisomes consist of a central core from which rods radiate. A large polypeptide (LCM, 75-120 kDa) is postulated to act both as terminal energy acceptor and as a linker polypeptide that stabilizes the phycobilisome architecture. We report here the characterization of the gene (apcE) that encodes this LCM polypeptide in Calothrix sp. PCC 7601. It is located upstream from the genes encoding the major components of the phycobilisome core (allophycocyanin) and is part of the same operon. The deduced amino acid sequence shows that the N-terminal region of LCM shares homology with the other phycobiliprotein subunits and thus constitutes the chromoprotein domain. The other part of the molecule is made up of four repeated domains that are highly homologous to the N-terminal regions of the phycocyanin rod linker polypeptides. The predicted secondary structure of the different domains of the LCM is discussed in relation to the different roles and properties of this large molecule.