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STRUCTURE AND ORGANIZATION OF THE PHOTOSYSTEM I COMPLEX

光系统 I 复合体的结构和组织

基本信息

批准号：
2857226
负责人：
PARAG R CHITNIS
金额：
$ 18.94万
依托单位：
IOWA STATE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
1995
资助国家：
美国
起止时间：
1995-08-02 至 2000-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/2857226
关键词：
Escherichia coli X ray crystallography biotin chloroplasts cofactor crosslink enzyme complex enzyme structure ferredoxin membrane proteins molecular cloning nucleic acid sequence oxidoreductase photosynthetic bacteria photosystem plastocyanin protein structure succinimides

项目摘要

Until now, structures of very few membrane-proteins have been determined at atomic resolution. We plan to study molecular organization of photosystem I and determine its structure at atomic resolution. Photosystem I, the light-dependent plastocyanin-ferredoxin oxidoreductase, is a heteromultimeric pigment-protein complex in the photo synthetic membranes of chloroplasts and cyanobacteria. It contains at least eleven proteins, 100 chlorophylls, beta-carotenes and a series of electron transfer centers. Photosystem I is a typical membrane-protein complex. Moreover, it is stable, abundant and easy to purify. Thus photosystem I is a suitable model system for structural analysis of membrane-protein complexes. We have embarked on a comprehensive project aimed to elucidate structure of photosystem I from the thermophilic cyanobacterium Mastigocladus laminosus. Our main objectives for this project are: (1) Topographical analysis of photosystem I organization. We will identify protein domains that are exposed on the surface of the complex or are involved in protein-protein interactions within the complex. NHS- biotinylation, protease accessibility, and chemical cross-linking studies will be used. The information generated by these methods will be used to orient structures of individual subunits in the complex. These data will also assist in correct identification of structural components revealed by X-ray crystallography. (2) Generation of simpler systems for structural analysis. We will determine primary structure of photosystem I proteins by cloning and sequencing the corresponding genes. We will overproduce peripheral subunits of photosystem I in E. coli and elucidate their structure by crystallography. We will also generate subunit-deficient mutants lacking the PsaF and PsaL proteins, thus engineering a complex that is simpler, more hydrophilic, but still functional. (3) X-ray diffraction analysis: We will crystallize entire and simpler photosystem l complexes as well as the overexpressed proteins. We plan to determine their structures from analysis of X-ray diffraction patterns. Finally we will integrate biochemical and X-ray crystallographic data to propose model for the detailed structure of photosystem I.

到目前为止，很少有膜蛋白的结构被确定以原子分辨率。我们计划研究光系统I并以原子分辨率确定其结构。光系统I，光依赖性质体蓝素-铁氧还蛋白氧化还原酶，是光合作用中的异源多聚体色素蛋白复合物，叶绿体和蓝细菌的膜。它至少包含11个蛋白质，100叶绿素，β-胡萝卜素和一系列的电子转移中心。光系统I是典型的膜蛋白复合物。此外，它是稳定的，丰富的，易于纯化。因此，光系统I是一个适用于膜蛋白结构分析的模型系统配合物我们已经开始了一个全面的项目，旨在阐明嗜热蓝细菌光系统I的结构 Mastigocladus laminosus.本项目的主要目标是： (1)光系统I组织的地形分析。我们将确定暴露在复合物表面上或参与蛋白质间的相互作用。NHS- 生物素化、蛋白酶可及性和化学交联研究将用于这些方法产生的信息将用于确定复合体中单个亚基的结构方向。这些数据将还有助于正确识别结构部件， X射线晶体学 (2)生成用于结构分析的更简单的系统。我们将通过克隆确定光系统I蛋白的一级结构，测序相应的基因。我们将过度生产外围设备光系统I亚基。大肠杆菌，并阐明其结构，结晶学我们还将产生缺乏亚基的突变体， PsaF和PsaL蛋白，从而工程化一种更简单的复合物，更具亲水性，但仍具有功能。 (3)X射线衍射分析：我们将结晶完整和更简单光系统L复合物以及过表达的蛋白质。我们计划通过X射线衍射图分析确定其结构。最后，我们将整合生物化学和X射线晶体学数据，提出了光系统I的详细结构模型。

项目成果

期刊论文数量（5）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

An insight into the assembly and organization of photosystem I complex in the thylakoid membranes of the thermophilic cyanobacterium, Mastigocladus laminosus.

深入了解嗜热蓝藻 Mastigocladus laaminosus 类囊体膜中光系统 I 复合体的组装和组织。

DOI：
发表时间：
2000
期刊：
Indian journal of biochemistry & biophysics.
影响因子：
0
作者：
Lushy,A;He,Z;Fish,A;Darash-Yahana,M;Minai,L;Verchovsky,L;Michaeli,D;Nechushtai,R
通讯作者：
Nechushtai,R

Isolation and functional study of photosystem I subunits in the cyanobacterium Synechocystis sp. PCC 6803.