Ycf12 is a core subunit in the photosystem II complex
Ycf12 is a core subunit in the photosystem II complex
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DOI：
10.1016/j.bbabio.2007.08.008
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发表时间：
2007-11-01
影响因子：
4.3
通讯作者：
Sugiura, Miwa
中科院分区：
文献类型：
--
作者：
Kashino, Yasuhiro;Takahashi, Takeshi;Sugiura, Miwa
最新的蓝藻光系统II(PS II)核心复合体的结晶学模型在原有模型的基础上增加了一个跨膜低分子量(LMW)组分，这表明PS II中存在一个未知的跨膜LMW组分。我们研究了来自长热球菌的高纯度完整PS II核心复合体的多肽组成，以鉴定未知组分。利用一个专门用于分离LMW疏水蛋白的电泳仪，一个新的约5 kDa的蛋白被鉴定为PS II组分。其N端氨基酸序列与Ycf12相同。相应的基因被称为YCF(假设的叶绿体阅读框架)基因之一，ycf12，在叶绿体和蓝藻基因组中广泛保守。尽管如此，该基因产物的定位和功能从未被指定。我们的发现首次表明，ycf12实际上是作为PS II复合体的一个组成部分在细胞中表达的，这揭示了PS II核心复合体中存在一种先前未知的跨膜蛋白。(C)2007爱思唯尔B.保留所有权利。
The latest crystallographic model of the cyanobacterial photosystem II (PS II) core complex added one transmembrane low molecular weight (LMW) component to the previous model, suggesting the presence of an unknown transmembrane LMW component in PS II. We have investigated the polypeptide composition in highly purified intact PS II core complexes from Thermosynechococcus elongatus, the species which yielded the PS II crystallographic models described above, to identify the unknown component. Using an electrophoresis system specialized for separation of LMW hydrophobic proteins, a novel protein of similar to 5 kDa was identified as a PS II component. Its N-terminal amino acid sequence was identical to that of Ycf12. The corresponding gene is known as one of the ycf (hypothetical chloroplast reading frame) genes, ycf12, and is widely conserved in chloroplast and cyanobacterial genomes. Nonetheless, the localization and function of the gene product have never been assigned. Our finding shows, for the first time, that ycf12 is actually expressed as a component of the PS II complex in the cell, revealing that a previously unidentified transmembrane protein exists in the PS II core complex. (c) 2007 Elsevier B. All rights reserved.