Type III restriction endonucleases are heterotrimeric: comprising one helicase-nuclease subunit and a dimeric methyltransferase that binds only one specific DNA.
Type III restriction endonucleases are heterotrimeric: comprising one helicase-nuclease subunit and a dimeric methyltransferase that binds only one specific DNA.
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III型限制性核酸内切酶是异三聚体：包含一个仅结合一个特定DNA的二聚体甲基核酸酶亚基和一个二聚体甲基转移酶。
DOI：
10.1093/nar/gku122
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发表时间：
2014-04
影响因子：
14.9
通讯作者：
Tóth J
中科院分区：
文献类型：
--
作者：
Butterer A;Pernstich C;Smith RM;Sobott F;Szczelkun MD;Tóth J
尽管在过去的几十年里，许多研究小组已经确定了III型限制性内切酶的生物化学的基本方面，但仍然没有得到解决。其中一个特征是这些异寡聚酶复合体的亚基化学计量比，这对反应机理具有重要的意义。在这项研究中，我们给出了一系列自然质谱学和尺寸排除层析的结果，多角度光散射符合EcoP15I、EcoPI和PstII复合体中Res和Mod亚基的1：2比例为主要全酶物种，以及EcoP15I和EcoPI结合的特异性DNA(SDNA)的1：1化学计量比。我们的数据也与一个模型一致，该模型认为识别位点结合激活的ATP水解会导致酶从位点释放，通过游离DNA末端从底物解离，并切割DNA。根据已发表的文献对这些结果进行了批判性的讨论，旨在从反应机理的角度解决争议并讨论后果。
Fundamental aspects of the biochemistry of Type III restriction endonucleases remain unresolved despite being characterized by numerous research groups in the past decades. One such feature is the subunit stoichiometry of these hetero-oligomeric enzyme complexes, which has important implications for the reaction mechanism. In this study, we present a series of results obtained by native mass spectrometry and size exclusion chromatography with multi-angle light scattering consistent with a 1:2 ratio of Res to Mod subunits in the EcoP15I, EcoPI and PstII complexes as the main holoenzyme species and a 1:1 stoichiometry of specific DNA (sDNA) binding by EcoP15I and EcoPI. Our data are also consistent with a model where ATP hydrolysis activated by recognition site binding leads to release of the enzyme from the site, dissociation from the substrate via a free DNA end and cleavage of the DNA. These results are discussed critically in the light of the published literature, aiming to resolve controversies and discuss consequences in terms of the reaction mechanism.
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DOI：
10.1007/s13361-012-0393-z
发表时间：
2012-07-01
影响因子：
3.2
作者：
Hall, Zoe;Robinson, Carol V.
通讯作者：
Robinson, Carol V.
影响因子：
--
作者：
Bheemanaik S;Sistla S;Krishnamurthy V;Arathi S;Desirazu NR
通讯作者：
Desirazu NR
影响因子：
10.5
作者：
Kennaway, Christopher K.;Taylor, James E.;Dryden, David T. F.
通讯作者：
Dryden, David T. F.
影响因子：
5.6
作者：
Gupta, Yogesh K.;Yang, Lin;Aggarwal, Aneel K.
通讯作者：
Aggarwal, Aneel K.
影响因子：
5.6
作者：
HADI, SM;BACHI, B;BICKLE, TA
通讯作者：
BICKLE, TA