Conserved amino acids in each subunit of the heteroligomeric tRNA m1A58 Mtase from Saccharomyces cerevisiae contribute to tRNA binding.
Conserved amino acids in each subunit of the heteroligomeric tRNA m1A58 Mtase from Saccharomyces cerevisiae contribute to tRNA binding.
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DOI：
10.1093/nar/gkm574
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发表时间：
2007
影响因子：
14.9
通讯作者：
Anderson JT
中科院分区：
文献类型：
--
作者：
Ozanick SG;Bujnicki JM;Sem DS;Anderson JT
在酿酒酵母中，由必需基因 TRM6 和 TRM61 编码的双亚基甲基转移酶 (Mtase) 负责形成 1-甲基腺苷，这是一种在 tRNA 的 58 位发现的修饰核苷，对于 tRNA 的稳定性至关重要。来自结核分枝杆菌的同源四聚体 m1A58 tRNA Mtase (TrmI) 的晶体结构已得到解析，并用作模板来构建酵母 m1A58 tRNA Mtase 异四聚体模型。我们改变了 TRM6 和 TRM61 中的氨基酸，根据该模型预测这些氨基酸对于异源低聚物的稳定性很重要。表达 trm6 和 trm61 突变体的酵母菌株表现出表明 m1A 形成减少的生长表型。此外，重组突变酶还降低了体外 Mtase 活性。我们证明引入的突变不会阻止异寡聚体的形成，也不会破坏辅因子 S-腺苷-L-甲硫氨酸的结合。相反，Trm6p 或 Trm61p 中的氨基酸取代破坏了酵母 m1A58 tRNA Mtase 结合的能力，表明每个亚基都有助于 tRNA 结合，并表明当这些突变存在时，底物结合袋会发生结构改变。
In Saccharomyces cerevisiae, a two-subunit methyltransferase (Mtase) encoded by the essential genes TRM6 and TRM61 is responsible for the formation of 1-methyladenosine, a modified nucleoside found at position 58 in tRNA that is critical for the stability of . The crystal structure of the homotetrameric m1A58 tRNA Mtase from Mycobacterium tuberculosis, TrmI, has been solved and was used as a template to build a model of the yeast m1A58 tRNA Mtase heterotetramer. We altered amino acids in TRM6 and TRM61 that were predicted to be important for the stability of the heteroligomer based on this model. Yeast strains expressing trm6 and trm61 mutants exhibited growth phenotypes indicative of reduced m1A formation. In addition, recombinant mutant enzymes had reduced in vitro Mtase activity. We demonstrate that the mutations introduced do not prevent heteroligomer formation and do not disrupt binding of the cofactor S-adenosyl-l-methionine. Instead, amino acid substitutions in either Trm6p or Trm61p destroy the ability of the yeast m1A58 tRNA Mtase to bind , indicating that each subunit contributes to tRNA binding and suggesting a structural alteration of the substrate-binding pocket occurs when these mutations are present.
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影响因子：
14.9
作者：
Jiang, HQ;Motorin, Y;Grosjean, H
通讯作者：
Grosjean, H
影响因子：
5.3
作者：
HARASHIMA, S;HINNEBUSCH, AG
通讯作者：
HINNEBUSCH, AG
影响因子：
3.2
作者：
ITO, H;FUKUDA, Y;KIMURA, A
通讯作者：
KIMURA, A
影响因子：
14.9
作者：
Dunin-Horkawicz, Stanislaw;Czerwoniec, Anna;Gajda, Michal J.;Feder, Marcin;Grosjean, Henri;Bujnicki, Janusz M.
通讯作者：
Bujnicki, Janusz M.
影响因子：
10.5
作者：
GARCIABARRIO, MT;NARANDA, T;TAMAME, M
通讯作者：
TAMAME, M