Interaction of bovine mitochondrial ribosomes with Escherichia coli initiation factor 3 (IF3).
Interaction of bovine mitochondrial ribosomes with Escherichia coli initiation factor 3 (IF3).
复制标题
牛线粒体核糖体与大肠杆菌起始因子 3 (IF3) 的相互作用。
DOI：
10.1021/bi00409a059
复制
发表时间：
1988
期刊：
影响因子：
2.9
通讯作者：
O'Brien,TW
中科院分区：
文献类型：
--
作者：
Denslow,ND;LiCata,VJ;Gualerzi,C;O'Brien,TW
Revised Manuscript Received January 8, 1988 abstract: Mammalian mitochondrial ribosomes are distinguished from their bacterial and eukaryotic-cytoplasmic counterparts, as well as from mitochondrial ribosomes of lower eukaryotes, by their physical and chemical properties and their high proteincontent. However, they do share more functional homologies with bacterial ribosomes than with cytoplasmic ribosomes. To search for possible homologies between mammalian mitochondrial ribosomesand bacterial ribosomesat the level of initiation factor binding sites, we studied the interaction of Escherichia coli initiation factor 3 (IF3) with bovine mitochondrial ribosomes. Bacterial IF3 was found to bind to the small subunit of bovine mitochondrial ribosomes with an affinity of the same order of magnitude as that for bacterial ribosomes, suggesting that most of the functional groups contributing to the IF3 binding site inbacterial ribosomes are conserved in mitochondrial ribosomes. Increasing ionic strength affects binding to both ribosomes similarly and suggests a large electrostatic contribution to the reaction. Furthermore, bacterial IF3 inhibits the Mg2+-dependent association of mitochondrial ribosomal subunits, suggesting that the bacterial IF3 binds to mitochondrial small subunits in a functional way. e translation system of mammalian mitochondria is unique in many aspects, including the composition and physical-chemical properties of the ribosomes (O’Brien, 1976; Matthews et al., 1982), the structure of the tRNAs (de Bruijn & Klug, 1983), and the requirements for some homologous soluble factors (Denslow & O’Brien, 1978, 1979; Eberly et al., 1985). Several properties of the ribosomes distinguish them from those of prokaryotes and the cytoplasm of eukaryotes. Having about the same mass as bacterial ribosomes, they contain only half as much rRNA and nearly twice as much protein, differences which affect their sedimentation coefficient and buoyant density (Hamilton & O’Brien, 1974; Sacchi et al., 1973). In addition, the mitochondrial r-proteins are unique and have no closely related homologues in bacterial or eukaryotic-cyto-plasmic ribosomes that have been identified by electrophoretic mobility or by immunologic cross-reactivity (S. Pietromonaco and T. W. O’Brien unpublished observation; Matthews et al., 1982). Despite many attempts in different laboratories, no reproducible in vitro translation system has yet been developed for mammalian mitochondria. Unlike mitochondrial systems from fungi (Grandi & Kuntzel, 1970; Richter & Lipmann, 1970; Piechulla & Kuntzel, 1983), the mammalian mitochondrial translation system has not been well characterized, and only limited information exists regarding the identity and properties of any specific protein factors involved. On the basis of several partial reactions of protein synthesis, including the fragment reaction (Denslow & O’Brien, 1978), poly (U)-dependent phenylalanine polymerization (Denslow & O’Brien, 1979; Ulbrich et al., 1980; Eberly et al., 1985), and GTPase activity
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猫视网膜神经节细胞的超敏度。
DOI：
10.1126/science.3945816
发表时间：
1986
期刊：
Science (New York, N.Y.)
影响因子：
--
作者：
Shapley,R;Victor,J
通讯作者：
Victor,J
DOI：
--
发表时间：
--
期刊：
Journal of Physiology
影响因子：
--
作者：
H. Hartridge
通讯作者：
H. Hartridge
空间定位和超敏锐度：中心/周围定位贡献函数有两个基础
影响因子：
1.8
作者：
D. Badcock;G. Westheimer
通讯作者：
G. Westheimer
影响因子：
1.8
作者：
WATT, RJ;MORGAN, MJ
通讯作者：
MORGAN, MJ
视觉超敏锐度的整合区域
影响因子：
1.8
作者：
G. Westheimer;S. McKee
通讯作者：
S. McKee