Enhanced Binding Affinity for an i-Motif DNA Substrate Exhibited by a Protein Containing Nucleobase Amino Acids.
Enhanced Binding Affinity for an i-Motif DNA Substrate Exhibited by a Protein Containing Nucleobase Amino Acids.
复制标题
DOI：
10.1021/jacs.6b11825
复制
发表时间：
2017-04-05
影响因子：
15
通讯作者：
Hecht SM
中科院分区：
文献类型：
--
作者：
Bai X;Talukder P;Daskalova SM;Roy B;Chen S;Li Z;Dedkova LM;Hecht SM
几种变体的核酸结合基序（RRM 1）的假定的转录因子hnRNP LL含有核碱基氨基酸在特定的位置已经制备和用于研究BCL 2的i-基序DNA的结合亲和力。分子模拟表明，RRM 1中的许多氨基酸可能参与与i基序DNA的相互作用，并选择His 24和Arg 26进行修饰，这是基于它们与i基序DNA的G14相互作用的潜在能力。将四个核碱基氨基酸在位置24和26中的一个或两个处引入RRMl中。将胞嘧啶核碱基2引入RRM 1的24位增加了修饰蛋白对i基序DNA的亲和力，这与2和G14可能的沃森-克里克相互作用一致。相比之下，尿嘧啶核碱基3的引入对DNA亲和力的影响最小。两个结构简化的核碱基类似物（1和4）缺乏的N-1和2-氧代取代基也被引入代替His 24。同样，含有1的RRM 1类似物表现出对i基序DNA的增强的亲和力，而含有4的蛋白质类似物与DNA底物的结合不那么紧密。最后，含有1代替Arg 26的修饰蛋白也比野生型蛋白更强地结合到i基序DNA，但是在位置24和26处均含有1的蛋白与DNA的结合比野生型弱。这些结果支持了利用核碱基氨基酸作为蛋白质组分来控制和增强DNA-蛋白质相互作用的想法。最后，在G14处修饰i基序DNA减少了RRM 1-DNA相互作用，以及核碱基氨基酸1稳定RRM 1-DNA相互作用的能力。
Several variants of a nucleic acid binding motif (RRM1) of putative transcription factor hnRNP LL containing nucleobase amino acids at specific positions have been prepared and used to study binding affinity for the BCL2 i-motif DNA. Molecular modeling suggested a number of amino acids in RRM1 likely to be involved in interaction with the i-motif DNA, and His24 and Arg26 were chosen for modification based on their potential ability to interact with G14 of the i-motif DNA. Four nucleobase amino acids were introduced into RRM1 at one or both of positions 24 and 26. The introduction of cytosine nucleobase 2 into position 24 of RRM1 increased the affinity of the modified protein for the i-motif DNA, consistent with the possible Watson–Crick interaction of 2 and G14. In comparison, the introduction of uracil nucleobase 3 had a minimal effect on DNA affinity. Two structurally simplified nucleobase analogues (1 and 4) lacking both the N-1 and the 2-oxo substituents were also introduced in lieu of His24. Again, the RRM1 analogue containing 1 exhibited enhanced affinity for the i-motif DNA, while the protein analogue containing 4 bound less tightly to the DNA substrate. Finally, the modified protein containing 1 in lieu of Arg26 also bound to the i-motif DNA more strongly than the wild-type protein, but a protein containing 1 both at positions 24 and 26 bound to the DNA less strongly than wild type. The results support the idea of using nucleobase amino acids as protein constituents for controlling and enhancing DNA–protein interaction. Finally, modification of the i-motif DNA at G14 diminished RRM1–DNA interaction, as well as the ability of nucleobase amino acid 1 to stabilize RRM1–DNA interaction.
登录
查看更多内容
影响因子：
3.5
作者：
Talukder P;Dedkova LM;Ellington AD;Yakovchuk P;Lim J;Anslyn EV;Hecht SM
通讯作者：
Hecht SM
影响因子：
15
作者：
Maini R;Dedkova LM;Paul R;Madathil MM;Chowdhury SR;Chen S;Hecht SM
通讯作者：
Hecht SM
影响因子：
14.9
作者：
ROBERTSON, SA;NOREN, CJ;SCHULTZ, PG
通讯作者：
SCHULTZ, PG
影响因子：
15
作者：
Roy, Basab;Talukder, Poulami;Hecht, Sidney M.
通讯作者：
Hecht, Sidney M.
影响因子：
14.8
作者：
通讯作者：
--