Centre for mRNP Biogenesis and Metabolism, Gustav Wieds Vej 10c, Aarhus University, DK-8000 Aarhus C, Denmark; Department of Molecular Biology and Genetics, Gustav Wieds Vej 10c, Aarhus University, DK-8000 Aarhus C, Denmark.
Department of Biomedicine, Ole Worms Allé 6, Aarhus University, DK-8000 Aarhus C, Denmark.
Biochem Biophys Res Commun. 2014 Jul 18;450(1):634-40. doi: 10.1016/j.bbrc.2014.06.032. Epub 2014 Jun 14.
The RNase D-type 3'-5' exonuclease Rrp6p from Saccharomyces cerevisiae is a nuclear-specific cofactor of the RNA exosome and associates in vivo with Rrp47p (Lrp1p). Here, we show using biochemistry and small-angle X-ray scattering (SAXS) that Rrp6p and Rrp47p associate into a stable, heterodimeric complex with an elongated shape consistent with binding of Rrp47p to the nuclease domain and opposite of the HRDC domain of Rrp6p. Rrp47p reduces the exonucleolytic activity of Rrp6p on both single-stranded and structured RNA substrates without significantly altering the affinity towards RNA or the ability of Rrp6p to degrade RNA secondary structure.
酿酒酵母中的 RNase D 型 3'-5' 外切核酸酶 Rrp6p 是 RNA 外切体的核特异性辅助因子，并且在体内与 Rrp47p（Lrp1p）结合。在这里，我们使用生物化学和小角度 X 射线散射（SAXS）表明 Rrp6p 和 Rrp47p 形成一个稳定的异二聚体复合物，具有与 Rrp47p 结合到核酸酶结构域一致的细长形状，而与 Rrp6p 的 HRDC 结构域相反。Rrp47p 降低了 Rrp6p 在单链和结构 RNA 底物上的外切核酸酶活性，而对 RNA 的亲和力或 Rrp6p 降解 RNA 二级结构的能力没有显著影响。
