3NEJ

Q28E mutant of Hera RNA helicase N-terminal domain - perfectly twinned hexagonal form

3NEJ の概要

• エントリーDOI: 10.2210/pdb3nej/pdb
• 関連するPDBエントリー: 2GXS 3MWJ 3MWK 3MWL 3NBF
• 分子名称: Heat resistant RNA dependent ATPase (2 entities in total)
• 機能のキーワード: rna helicase, ribosome biogenesis, thermophilic, hydrolase, atpase
• 由来する生物種: Thermus thermophilus
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 44687.88

構造登録者

Rudolph, M.G. (登録日: 2010-06-09, 公開日: 2011-04-27, 最終更新日: 2023-11-01)

主引用文献

Strohmeier, J.,Hertel, I.,Diederichsen, U.,Rudolph, M.G.,Klostermeier, D.
Changing nucleotide specificity of the DEAD-box helicase Hera abrogates communication between the Q-motif and the P-loop.
Biol.Chem., 392:357-369, 2011

PubMed Abstract: DEAD-box proteins disrupt or remodel RNA and protein/RNA complexes at the expense of ATP. The catalytic core is composed of two flexibly connected RecA-like domains. The N-terminal domain contains most of the motifs involved in nucleotide binding and serves as a minimalistic model for helicase/nucleotide interactions. A single conserved glutamine in the so-called Q-motif has been suggested as a conformational sensor for the nucleotide state. To reprogram the Thermus thermophilus RNA helicase Hera for use of oxo-ATP instead of ATP and to investigate the sensor function of the Q-motif, we analyzed helicase activity of Hera Q28E. Crystal structures of the Hera N-terminal domain Q28E mutant (TthDEAD_Q28E) in apo- and ligand-bound forms show that Q28E does change specificity from adenine to 8-oxoadenine. However, significant structural changes accompany the Q28E mutation, which prevent the P-loop from adopting its catalytically active conformation and explain the lack of helicase activity of Hera_Q28E with either ATP or 8-oxo-ATP as energy sources. 8-Oxo-adenosine, 8-oxo-AMP, and 8-oxo-ADP weakly bind to TthDEAD_Q28E but in non-canonical modes. These results indicate that the Q-motif not only senses the nucleotide state of the helicase but could also stabilize a catalytically competent conformation of the P-loop and other helicase signature motifs.

PubMed: 21391900
DOI: 10.1515/BC.2011.034

実験手法

X-RAY DIFFRACTION (2.57 Å)