Imino proton NMR analysis of HDV ribozymes:: nested double pseudoknot structure and Mg2+ ion-binding site close to the catalytic core in solution

被引：30

作者：

Tanaka, Y ^{[1
]}

Hori, T ^{[1
]}

Tagaya, M ^{[1
]}

Sakamoto, T ^{[1
]}

Kurihara, Y ^{[1
]}

Katahira, M ^{[1
]}

Uesugi, S ^{[1
]}

机构：

[1] Yokohama Natl Univ, Grad Sch Environm & Informat Sci, Dept Environm & Nat Sci, Hodogaya Ku, Yokohama, Kanagawa 2408501, Japan

来源：

NUCLEIC ACIDS RESEARCH | 2002年 / 30卷 / 03期

关键词：

D O I：

10.1093/nar/30.3.766

中图分类号：

Q5 [生物化学]; Q7 [分子生物学];

学科分类号：

071010 ; 081704 ;

摘要：

Minimized trans-acting HDV ribozyme systems consisting of three (Rz-3) and two (Rz-2) RNA strands were prepared and their folding conformations were analyzed by NMR spectroscopy. The guanosine residues in one of the enzyme components of Rz-3 were labeled with C-13 and N-15. Imino proton signals were assigned by analysis of NOESY and HSQC spectra. The results are consistent with the nested double pseudoknot model, which contains novel base pairs (P1.1), as observed in the crystal structure of a genomic HDV ribozyme. The NOE connectivities suggest an additional G:G pair at the bottom of P1.1 and at the top of P4. The effects of temperature and Mg2+ ions on base pairs for Rz-3 were examined. The temperature variation experiment on Rz-3 showed that P3 is the most stable and that P1.1 is as stable as P1 and P2. The imino proton signals of the G:U pair at the bottom of P1 and the top of P1.1, which are close to the cleavage site, showed the largest changes upon Mg2+ titration of Rz-3. The results suggest that the catalytic Mg2+ ion binds to the pocket formed by P1 and L3.

引用

页码：766 / 774

页数：9