Binding synergy as an essential step for tRNA editing and modification enzyme codependence in Trypanosoma brucei.
Binding synergy as an essential step for tRNA editing and modification enzyme codependence in Trypanosoma brucei.
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DOI：
10.1261/rna.062893.117
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发表时间：
2018-01
期刊：
影响因子：
--
通讯作者：
Alfonzo JD
中科院分区：
文献类型：
--
作者：
McKenney KM;Rubio MAT;Alfonzo JD
转移RNA在其成熟过程中获得各种天然存在的化学修饰;这些修饰以对蛋白质合成至关重要的方式微调其结构和解码特性。我们最近报道，在真核寄生虫，布氏锥虫，甲基化和脱氨事件是出乎意料地相互关联，从而tRNA腺苷脱氨酶（TbADAT 2/3）和3-甲基胞嘧啶甲基转移酶（TbTrm 140）严格依赖于彼此的活动，导致形成m3 C和m3 U在位置32在几个tRNA。然而，目前尚不清楚为什么这两种在其他系统中独立工作的酶在T.布鲁塞。在这里，我们表明，这些酶表现出结合的协同作用，或相互增加的结合亲和力，这是超过部分的总和，当加在一起的反应。虽然这些酶直接相互作用，tRNA结合试验中使用的关键结合和催化位点突变的酶的变体表明，观察到的结合协同作用源于贡献从tRNA结合域远端的活性位点。这些结果为这些蛋白质的已知相互作用提供了理论基础，同时也说明了看似不相关的酶之间底物特异性的调节。这一信息应该是有价值的，在进一步了解tRNA修饰酶如何共同作用，以调节基因的表达在转录后水平，并提供了一个基础，这种活动的相互依赖性。
Transfer RNAs acquire a variety of naturally occurring chemical modifications during their maturation; these fine-tune their structure and decoding properties in a manner critical for protein synthesis. We recently reported that in the eukaryotic parasite, Trypanosoma brucei, a methylation and deamination event are unexpectedly interconnected, whereby the tRNA adenosine deaminase (TbADAT2/3) and the 3-methylcytosine methyltransferase (TbTrm140) strictly rely on each other for activity, leading to formation of m3C and m3U at position 32 in several tRNAs. Still however, it is not clear why these two enzymes, which work independently in other systems, are strictly codependent in T. brucei. Here, we show that these enzymes exhibit binding synergism, or a mutual increase in binding affinity, that is more than the sum of the parts, when added together in a reaction. Although these enzymes interact directly with each other, tRNA binding assays using enzyme variants mutated in critical binding and catalytic sites indicate that the observed binding synergy stems from contributions from tRNA-binding domains distal to their active sites. These results provide a rationale for the known interactions of these proteins, while also speaking to the modulation of substrate specificity between seemingly unrelated enzymes. This information should be of value in furthering our understanding of how tRNA modification enzymes act together to regulate gene expression at the post-transcriptional level and provide a basis for the interdependence of such activities.
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DOI：
10.1261/rna.056259.116
发表时间：
2016-09
期刊：
RNA (New York, N.Y.)
影响因子：
--
作者：
Arimbasseri AG;Iben J;Wei FY;Rijal K;Tomizawa K;Hafner M;Maraia RJ
通讯作者：
Maraia RJ
影响因子：
14.9
作者：
GROSJEAN, H;CONSTANTINESCO, F;BENACHENHOU, N
通讯作者：
BENACHENHOU, N
影响因子：
4.5
作者：
Alexandrov, A;Martzen, MR;Phizicky, EM
通讯作者：
Phizicky, EM
影响因子：
3.7
作者：
Chen C;Chen C;Moyzis R;Stern H;He Q;Li H;Li J;Zhu B;Dong Q
通讯作者：
Dong Q
影响因子：
5.3
作者：
Kalhor, HR;Clarke, S
通讯作者：
Clarke, S