Structural analysis of the multienzyme aminoacyl-tRNA synthetase complex: A three-domain model based on reversible chemical crosslinking
Structural analysis of the multienzyme aminoacyl-tRNA synthetase complex: A three-domain model based on reversible chemical crosslinking
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DOI：
10.1002/pro.5560070108
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发表时间：
1998-01-01
期刊：
影响因子：
8
通讯作者：
Warrington, JA
中科院分区：
文献类型：
--
作者：
Norcum, MT;Warrington, JA
真核生物氨酰-tRNA合成酶（a-RS）的一个子集包含在一个多酶复合物中，其结构细节知之甚少。三种可逆的化学交联试剂已被用来研究从兔网织红细胞中分离的这种颗粒内的多肽的排列。通过二维SDS对角凝胶电泳完成交联蛋白对的鉴定。已经鉴定了17个相邻的蛋白质对。至少使用两种试剂观察到8种：K-RS：p38、D-RS：K-RS、R-RS二聚体、K-RS二聚体、K-RS：Q-RS、E/P-RS：K-RS、E/P-RS：I-RS和Q-RS与一种非合成酶蛋白。使用一种试剂观察到另外9种：D-RS二聚体、R-RS：p43、D-RS：Q-RS、D-RS：M-RS、K-RS：L-RS、I-RS：R-RS、D-RS：E/P-RS、I-RS：Q-RS、I-RS：L-RS。一个三聚体协会被视为：E/P-RS：I-RS：L-RS。观察到的相邻蛋白质对内的氨酰-tRNA合成酶复合物的多肽分布在三个结构域相似的质量。这些可以排列成U形颗粒，其中每个“臂”被认为是一个域，第三个形成结构的“基础”。臂被称为结构域I（D-RS、M-RS、Q-RS）和结构域II（K-RS、R-RS），结构域III（E/P-RS、I-RS、L-RS）被分配给碱基。较小的蛋白质（p38、p43）可以桥接这些结构域。这些领域的空间关系，以及它们的组成，与早期的研究是一致的。因此，这项研究提供了一个初始的三维工作模型的多酶氨酰-tRNA合成酶复合物内的多肽的安排。
A subset of eukaryotic aminoacyl-tRNA synthetases (a-RS) are contained in a multienzyme complex for which little structural detail is known. Three reversible chemical crosslinking reagents have been used to investigate the arrangement of polypeptides within this particle as isolated from rabbit reticulocytes. Identification of the crosslinked protein pairs was accomplished by two-dimensional SDS diagonal gel electrophoresis. Seventeen neighboring protein pairs have been identified. Eight are seen with at least two reagents: K-RS:p38, D-RS:K-RS, R-RS dimer, K-RS dimer, K-RS:Q-RS, E/P-RS:K-RS, E/P-RS:I-RS, and Q-RS with one of the nonsynthetase proteins. Nine more are observed with one reagent: D-RS dimer, R-RS:p43, D-RS:Q-RS, D-RS:M-RS, K-RS:L-RS, I-RS:R-RS, D-RS:E/P-RS, I-RS:Q-RS, I-RS:L-RS. One trimeric association is seen: E/P-RS:I-RS:L-RS.The observed neighboring protein pairs suggest that the polypeptides within the aminoacyl-tRNA synthetase complex are distributed in three structural domains of similar mass. These can be arranged in a U-shaped particle in which each "arm" is considered a domain and the third forms the "base" of the structure. The arms have been termed domain I (D-RS, M-RS, Q-RS) and domain II (K-RS, R-RS), with domain III (E/P-RS, I-RS, L-RS) assigned to the base. The smaller proteins (p38, p43) may bridge the domains. This proposed spatial relationship of these domains, as well as their compositions, are consistent with earlier studies. Thus, this study provides an initial three-dimensional working model of the arrangement of polypeptides within the multienzyme aminoacyl-tRNA synthetase complex.