報文

NMR 法によるRNA の立体構造解析における
残余双極子相互作用の効果

馬場清喜，清宮恭子，木村友美，冨士原和也，染谷龍彦，坂本泰一，河合剛太

　　The global conformation of long RNA molecules containing bulge or internal loop are typically not well characterized by conventional NMR methods that rely on NOE-derived short-range distance restraints and J-coupling derived torsion angle restraints. Recently, residual dipolar couplings (RDCs) that provide long-range angular information are being used for structure determination of bio-molecules including RNAs. In this study, RDCs were used for structural determination of a model RNA including bulge, and the effect of RDCs on the structure determination was analyzed. The global structure of the model RNA was improved by refinement with RDCs. Furthermore, the local structure of the bulge was significantly improved, despite RDCs in the bulge region was not included in the refinement. Thus, it was clearly shown that the RDC refinement was valuable for the structure determination of RNAs containing bulge or internal loop.

Keywords: NMR, RNA, RDC, structure, conformation

近年、溶液試料を用いたNMR法による立体構造解析法において、残余双極子相互作用（RDC）を利用する方法が開発され、RNAにも応用されつつある。本研究では、折れ曲がりを含む典型的なRNAモデル分子を用いてRDCの情報を加えた構造解析を行い、詳細に解析した。その結果、ステム部位に由来するRDCの情報を加えることにより、２つのステム間の相対位置が確定するとともに、それらに挟まれた部位の収束度も向上した。