A Chlorophyll a/b-binding Protein Homolog That Is Induced by Iron Deficiency Is Associated with Enlarged Photosystem I Units in the Eucaryotic Alga Dunaliella salina*
A Chlorophyll a/b-binding Protein Homolog That Is Induced by Iron Deficiency Is Associated with Enlarged Photosystem I Units in the Eucaryotic Alga Dunaliella salina*
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缺铁诱导的叶绿素 a/b 结合蛋白同源物与真核藻类杜氏盐藻中光系统 I 单位增大有关*
DOI：
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发表时间：
2006
影响因子：
4.8
通讯作者：
U. Pick
中科院分区：
文献类型：
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作者：
Tal Varsano;S. Wolf;U. Pick
适应的盐生杜氏盐藻铁剥夺涉及广泛的叶绿体形态，光合活性的变化，并诱导一个主要的45-kDa的叶绿体蛋白Tidi。蛋白水解肽的部分氨基酸测序表明Tidi类似于构成捕光天线复合物（LHC）的叶绿素a/b结合蛋白（Varsano，T.，Kaftan，D.，Pick，U。等人（2003）J. Plant Nutr. 26，2197-2210）。在这里，我们表明，Tidi共享最高的氨基酸序列相似性与捕光I叶绿素a/b结合蛋白从高等植物，但有一个扩展的脯氨酸丰富的N-末端结构域。Tidi的积累被铁补充逆转，其水平与光系统I（PS-I）反应中心蛋白呈负相关。在天然凝胶电泳中，Tidi与扩大的PS-I-LHC-I超复合物共迁移。单粒子电子显微镜分析表明，PS-I单位从铁缺乏的细胞是更大的（31和37 nm的直径）比PS-I单位从控制细胞（22 nm）。分离的复合物的77 K叶绿素荧光发射光谱表明，Tidi-LHC-I天线功能耦合到PS-I的反应中心。这些结果表明，Tidi作为副天线的PS-I。在藻类和蓝藻铁剥夺下的PS-I天线的扩大表明一个共同的限制，需要重新平衡两个光系统之间的能量分布。
Adaptation of the halotolerant alga Dunaliella salina to iron deprivation involves extensive changes of chloroplast morphology, photosynthetic activities, and induction of a major 45-kDa chloroplast protein termed Tidi. Partial amino acid sequencing of proteolytic peptides suggested that Tidi resembles chlorophyll a/b-binding proteins which compose light-harvesting antenna complexes (LHC) (Varsano, T., Kaftan, D., and Pick, U. (2003) J. Plant Nutr. 26, 2197-2210). Here we show that Tidi shares the highest amino acid sequence similarity with light-harvesting I chlorophyll a/b-binding proteins from higher plants but has an extended proline-rich N-terminal domain. The accumulation of Tidi is reversed by iron supplementation, and its level is inversely correlated with photosystem I (PS-I) reaction center proteins. In native gel electrophoresis, Tidi co-migrates with enlarged PS-I-LHC-I super-complexes. Single particle electron microscopy analysis revealed that PS-I units from iron-deficient cells are larger (31 and 37 nm in diameter) than PS-I units from control cells (22 nm). The 77 K chlorophyll fluorescence emission spectra of isolated complexes suggest that the Tidi-LHC-I antenna are functionally coupled to the reaction centers of PS-I. These findings indicate that Tidi acts as an accessory antenna of PS-I. The enlargement of PS-I antenna in algae and in cyanobacteria under iron deprivation suggests a common limitation that requires rebalancing of the energy distribution between the two photosystems.
影响因子：
3
作者：
Frank, J;Radermacher, M;Leith, A
通讯作者：
Leith, A