3M85

Archaeoglobus fulgidus exosome y70a with RNA bound to the active site

3M85 の概要

• エントリーDOI: 10.2210/pdb3m85/pdb
• 関連するPDBエントリー: 2BA1 3M7N
• 分子名称: Putative uncharacterized protein AF_0206, Probable exosome complex exonuclease 1, Probable exosome complex exonuclease 2, ... (6 entities in total)
• 機能のキーワード: exosome, rna, exonuclease, hydrolase, nuclease, hydrolase-rna complex, hydrolase/rna
• 由来する生物種: Archaeoglobus fulgidus; 詳細
• 細胞内の位置: Cytoplasm (Potential): O29757 O29756
• タンパク質・核酸の鎖数: 12
• 化学式量合計: 236771.72

構造登録者

Hartung, S.,Hopfner, K.-P. (登録日: 2010-03-17, 公開日: 2010-04-28, 最終更新日: 2023-11-01)

主引用文献

Hartung, S.,Niederberger, T.,Hartung, M.,Tresch, A.,Hopfner, K.-P.
Quantitative analysis of processive RNA degradation by the archaeal RNA exosome
Nucleic Acids Res., 38:5166-5176, 2010

PubMed Abstract: RNA exosomes are large multisubunit assemblies involved in controlled RNA processing. The archaeal exosome possesses a heterohexameric processing chamber with three RNase-PH-like active sites, capped by Rrp4- or Csl4-type subunits containing RNA-binding domains. RNA degradation by RNA exosomes has not been studied in a quantitative manner because of the complex kinetics involved, and exosome features contributing to efficient RNA degradation remain unclear. Here we derive a quantitative kinetic model for degradation of a model substrate by the archaeal exosome. Markov Chain Monte Carlo methods for parameter estimation allow for the comparison of reaction kinetics between different exosome variants and substrates. We show that long substrates are degraded in a processive and short RNA in a more distributive manner and that the cap proteins influence degradation speed. Our results, supported by small angle X-ray scattering, suggest that the Rrp4-type cap efficiently recruits RNA but prevents fast RNA degradation of longer RNAs by molecular friction, likely by RNA contacts to its unique KH-domain. We also show that formation of the RNase-PH like ring with entrapped RNA is not required for high catalytic efficiency, suggesting that the exosome chamber evolved for controlled processivity, rather than for catalytic chemistry in RNA decay.

PubMed: 20392821
DOI: 10.1093/nar/gkq238

実験手法

X-RAY DIFFRACTION (3 Å)