Active site residues and amino acid specificity of the ubiquitin carrier protein-binding RING-H2 finger domain
Active site residues and amino acid specificity of the ubiquitin carrier protein-binding RING-H2 finger domain
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DOI：
10.1074/jbc.m411127200
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发表时间：
2005-12-09
影响因子：
4.8
通讯作者：
Katoh, E
中科院分区：
文献类型：
--
作者：
Katoh, S;Tsunoda, Y;Katoh, E
EL5 是一种水稻泛素蛋白异肽连接酶 (E3)，含有 RING-H2 指结构域，可与稻泛素载体蛋白 UBC5b 相互作用。我们将点突变引入 EL5 RING-H2 指，以便在体外检测泛素化活性时可以鉴定与 OsUBC5b 功能相互作用的残基。基于EL5 RING-H2指/OsUBC5b NMR滴定实验的结果选择残基位置。这些RING-H2指残基形成或邻近OsUBC5b识别的浅槽。 EL5 的 E3 活性取决于位于凹槽中心的 Trp。我们根据金属螯合基序的类型对大米环指进行分类，即。 e. RING-H2 或 RING-HC，并根据保守的 EL5 样 Trp 的存在或不存在。我们讨论了 E3 活性和保守的色氨酸之间可能的关系。
EL5 is a rice ubiquitin- protein isopeptide ligase (E3) containing a RING-H2 finger domain that interacts with Oryza sativa (Os) UBC5b, a rice ubiquitin carrier protein. We introduced point mutations into the EL5 RING-H2 finger so that residues that functionally interact with OsUBC5b could be identified when assayed for ubiquitination activity in vitro. The residue positions were selected based on the results of an EL5 RING-H2 finger/OsUBC5b NMR titration experiment. These RING-H2 finger residues form or are adjacent to a shallow groove that is recognized by OsUBC5b. The E3 activity of EL5 is shown to be dependent on a Trp located at the center of the groove. We classified rice RING fingers according to the type of metal- chelating motif, i. e. RING-H2 or RING- HC, and according to the presence or absence of a conserved EL5-like Trp. We discuss the probable relationship between E3 activity and the conserved Trp.