Chelated Magnesium Logic Gate Regulates Riboswitch Pseudoknot Formation.
Chelated Magnesium Logic Gate Regulates Riboswitch Pseudoknot Formation.
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DOI：
10.1021/acs.jpcb.1c02467
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发表时间：
2021-06-24
期刊：
影响因子：
--
通讯作者：
Roy S
中科院分区：
文献类型：
--
作者：
Sarkar R;Jaiswar A;Hennelly SP;Onuchic JN;Sanbonmatsu KY;Roy S
镁在RNA的结构、动力学和功能中起着关键作用。螯合镁对RNA结构的精确微观影响还有待探索。已知镁通过其在RNA周围的扩散云，通过外层（水介导的），内层和通常螯合离子介导的相互作用起作用。实验发现的位点特异性螯合镁离子对SAM-1核糖开关适体在细菌中的构象动力学的作用，提出了一种机制。在高温下的生理混合盐环境中进行原子模拟观察到这种机制。模拟验证与硫代磷酸酯干涉映射实验，有助于确定关键的内球Mg 2+网站规定一个适当的初始分布的内部和外部球镁离子，以保持一价和二价盐的生理离子浓度。一个协调一致的作用，两个螯合镁离子是新发现的，因为两者的存在下，支持形成的假结。这就构成了一个逻辑与门。这些镁离子中的任何一种的缺乏引起长距离假结相互作用的解离，暴露RNA的内核。一个基地三重是震中的镁螯合作用。它通过支持镁螯合在保护RNA的功能折叠中的直接作用来变构控制RNA假结，以控制ON和OFF转录转换。
Magnesium plays a critical role in the structure, dynamics, and function of RNA. The precise microscopic effect of chelated magnesium on RNA structure is yet to be explored. Magnesium is known to act through its diffuse cloud around the RNA, through outer-sphere (water-mediated), inner sphere, and often chelated ion-mediated interactions. A mechanism is proposed for the role of experimentally discovered site-specific chelated magnesium ions on the conformational dynamics of SAM-I riboswitch aptamer in bacteria. This mechanism is observed with atomistic simulations performed in a physiological mixed salt environment at a high temperature. The simulations were validated with phosphorothioate interference mapping experiments that help to identify crucial inner-sphere Mg2+ sites prescribing an appropriate initial distribution of inner and outer-sphere magnesium ions to maintain a physiological ion concentration of monovalent and divalent salts. A concerted role of two chelated magnesium ions is newly discovered since the presence of both supports the formation of the pseudoknot. This constitutes a logical AND gate. The absence of any of these magnesium ions instigates the dissociation of long-range pseudoknot interaction exposing the inner core of the RNA. A base triple is the epicenter of the magnesium chelation effect. It allosterically controls RNA pseudoknot by bolstering the direct effect of magnesium chelation in protecting the functional fold of RNA to control ON and OFF transcription switching.
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影响因子：
2.9
作者：
Callahan, Karen M.;Casillas-Ituarte, Nadia N.;Tobias, Douglas J.
通讯作者：
Tobias, Douglas J.
影响因子：
5.5
作者：
Aduri, Raviprasad;Psciuk, Brian T.;SantaLucia, John, Jr.
通讯作者：
SantaLucia, John, Jr.
DOI：
10.1039/c0cp00111b
发表时间：
2010-07-28
期刊：
Physical chemistry chemical physics : PCCP
影响因子：
--
作者：
Dupradeau FY;Pigache A;Zaffran T;Savineau C;Lelong R;Grivel N;Lelong D;Rosanski W;Cieplak P
通讯作者：
Cieplak P
影响因子：
2.9
作者：
Grilley, Dan;Misra, Vinod;Draper, David E.
通讯作者：
Draper, David E.
影响因子：
5.6
作者：
Conn, GL;Gittis, AG;Draper, DE
通讯作者：
Draper, DE