FMN riboswitch aptamer symmetry facilitates conformational switching through mutually exclusive coaxial stacking configurations.
FMN riboswitch aptamer symmetry facilitates conformational switching through mutually exclusive coaxial stacking configurations.
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DOI：
10.1016/j.yjsbx.2020.100035
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发表时间：
2020
影响因子：
--
通讯作者：
Stagno JR
中科院分区：
文献类型：
--
作者：
Wilt HM;Yu P;Tan K;Wang YX;Stagno JR
了解核开关的载脂蛋白和全空状态有助于阐明配体诱导构象“切换”的各种机制，从而巩固其基因调节能力。然而，先前对FMN核开关的黄素单核苷酸（FMN）结合适体的结构研究表明，与配体结合相关的最小构象变化并不能充分解释开关行为的基础。我们已经确定了2.7-Å分辨率的无配体FMN核开关适体晶体结构，这与以前报道的结构不同，特别是在P1和P4螺旋的构象和方向上。接近对称的三级结构提供了一种机制，通过这种机制，两对相邻螺旋（P3/P4或P1/P6）中的一个分别在没有或存在配体的情况下以互斥的方式共线堆叠。这些结构的比较表明，包括P4和L4的茎环对于维持全局构象状态是重要的，在没有配体的情况下，不利于P1调节螺旋的形成。总之，这些结果为FMN核开关构象开关的结构基础提供了进一步的见解。
Knowledge of both apo and holo states of riboswitches aid in elucidating the various mechanisms of ligand-induced conformational “switching” that underpin their gene-regulating capabilities. Previous structural studies on the flavin mononucleotide (FMN)-binding aptamer of the FMN riboswitch, however, have revealed minimal conformational changes associated with ligand binding that do not adequately explain the basis for the switching behavior. We have determined a 2.7-Å resolution crystal structure of the ligand-free FMN riboswitch aptamer that is distinct from previously reported structures, particularly in the conformation and orientation of the P1 and P4 helices. The nearly symmetrical tertiary structure provides a mechanism by which one of two pairs of adjacent helices (P3/P4 or P1/P6) undergo collinear stacking in a mutually exclusive manner, in the absence or presence of ligand, respectively. Comparison of these structures suggests the stem-loop that includes P4 and L4 is important for maintaining a global conformational state that, in the absence of ligand, disfavors formation of the P1 regulatory helix. Together, these results provide further insight to the structural basis for conformational switching of the FMN riboswitch.
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影响因子：
6.7
作者：
Mulhbacher J;Brouillette E;Allard M;Fortier LC;Malouin F;Lafontaine DA
通讯作者：
Lafontaine DA
影响因子：
16.8
作者：
Li, Shuang;Su, Zhaoming;Zhang, Jinwei
通讯作者：
Zhang, Jinwei
影响因子：
64.8
作者：
Serganov, Alexander;Huang, Lili;Patel, Dinshaw J.
通讯作者：
Patel, Dinshaw J.
影响因子：
64.8
作者：
Serganov, Alexander;Huang, Lili;Patel, Dinshaw J.
通讯作者：
Patel, Dinshaw J.
影响因子：
6.1
作者：
Batey, Robert T.
通讯作者：
Batey, Robert T.