Institute of Microbiology and Molecular Biology; Heinrich-Buff-Ring; Giessen, Germany.
RNA Biol. 2013 Mar;10(3):415-24. doi: 10.4161/rna.23450. Epub 2013 Jan 16.
The archaeal RNA-degrading exosome contains a catalytically active hexameric core, an RNA-binding cap formed by Rrp4 and Csl4 and the protein annotated as DnaG (bacterial type primase) with so-far-unknown functions in RNA metabolism. We found that the archaeal DnaG binds to the Csl4-exosome but not to the Rrp4-exosome of Sulfolobus solfataricus. In vitro assays revealed that DnaG is a poly(A)-binding protein enhancing the degradation of adenine-rich transcripts by the Csl4-exosome. DnaG is the second poly(A)-binding protein besides Rrp4 in the heteromeric, RNA-binding cap of the S. solfataricus exosome. This apparently reflects the need for effective and selective recruitment of adenine-rich RNAs to the exosome in the RNA metabolism of S. solfataricus.
古菌 RNA 降解外切体含有一个具有催化活性的六聚体核心、由 Rrp4 和 Csl4 形成的 RNA 结合帽，以及一种被注释为 DnaG（细菌类型引发酶）的蛋白质，其在 RNA 代谢中的功能尚不清楚。我们发现古菌 DnaG 与 Sulfolobus solfataricus 的 Csl4-外切体结合，但不与 Rrp4-外切体结合。体外实验表明，DnaG 是一种多聚（A）结合蛋白，可增强 Csl4-外切体对富含腺嘌呤的转录物的降解。DnaG 是除 Rrp4 之外的第二种多聚（A）结合蛋白，存在于 S. solfataricus 外切体的异源 RNA 结合帽中。这显然反映了在 S. solfataricus 的 RNA 代谢中，需要有效地、选择性地将富含腺嘌呤的 RNA 招募到外切体中。
