1YRM

Crystal Structure of an RNA duplex containing site specific 2'-amine substitutions at a C-A mismatch

1YRM の概要

• エントリーDOI: 10.2210/pdb1yrm/pdb
• 分子名称: DNA/RNA (5'-R(*GP*CP*AP*GP*A)-D(P*(A5M))-R(P*UP*UP*AP*AP*AP*UP*CP*UP*GP*C)-3'), STRONTIUM ION (3 entities in total)
• 機能のキーワード: 2'-amine, rna, duplex, mismatch
• タンパク質・核酸の鎖数: 3
• 化学式量合計: 15418.52

構造登録者

Gherghe, C.M.,Krahn, J.M.,Weeks, K.M. (登録日: 2005-02-04, 公開日: 2005-10-18, 最終更新日: 2024-04-03)

主引用文献

Gherghe, C.M.,Krahn, J.M.,Weeks, K.M.
Crystal structures, reactivity and inferred acylation transition States for 2'-amine substituted RNA.
J.Am.Chem.Soc., 127:13622-13628, 2005

PubMed Abstract: Ribose 2'-amine substitutions are broadly useful as structural probes in nucleic acids. In addition, structure-selective chemical reaction at 2'-amine groups is a robust technology for interrogating local nucleotide flexibility and conformational changes in RNA and DNA. We analyzed crystal structures for several RNA duplexes containing 2'-amino cytidine (C(N)) residues that form either C(N)-G base pairs or C(N)-A mismatches. The 2'-amine substitution is readily accommodated in an A-form RNA helix and thus differs from the C2'-endo conformation observed for free nucleosides. The 2'-amide product structure was visualized directly by acylating a C(N)-A mismatch in intact crystals and is also compatible with A-form geometry. To visualize conformations able to facilitate formation of the amide-forming transition state, in which the amine nucleophile carries a positive partial charge, we analyzed crystals of the C(N)-A duplex at pH 5, where the 2'-amine is protonated. The protonated amine moves to form a strong electrostatic interaction with the 3'-phosphodiester. Taken together with solution-phase experiments, 2'-amine acylation is likely facilitated by either of two transition states, both involving precise positioning of the adjacent 3'-phosphodiester group.

PubMed: 16190727
DOI: 10.1021/ja053647y

実験手法

X-RAY DIFFRACTION (2.5 Å)