6S8Q

Human Brr2 Helicase Region in complex with C-tail deleted Jab1

6S8Q の概要

• エントリーDOI: 10.2210/pdb6s8q/pdb
• 分子名称: U5 small nuclear ribonucleoprotein 200 kDa helicase, Pre-mRNA-processing-splicing factor 8, SULFATE ION, ... (4 entities in total)
• 機能のキーワード: rnp remodeling, pre-mrna splicing, spliceosome catalytic activation, dexd/h-box rna helicase, rna and atp binding, nucleus, hydrolase
• 由来する生物種: Homo sapiens (Human); 詳細
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 229992.01

構造登録者

Santos, K.F.,Vester, K.,Wahl, M.C. (登録日: 2019-07-10, 公開日: 2020-01-22, 最終更新日: 2024-05-15)

主引用文献

Vester, K.,Santos, K.F.,Kuropka, B.,Weise, C.,Wahl, M.C.
The inactive C-terminal cassette of the dual-cassette RNA helicase BRR2 both stimulates and inhibits the activity of the N-terminal helicase unit.
J.Biol.Chem., 295:2097-2112, 2020

PubMed Abstract: The RNA helicase bad response to refrigeration 2 homolog (BRR2) is required for the activation of the spliceosome before the first catalytic step of RNA splicing. BRR2 represents a distinct subgroup of Ski2-like nucleic acid helicases whose members comprise tandem helicase cassettes. Only the N-terminal cassette of BRR2 is an active ATPase and can unwind substrate RNAs. The C-terminal cassette represents a pseudoenzyme that can stimulate RNA-related activities of the N-terminal cassette. However, the molecular mechanisms by which the C-terminal cassette modulates the activities of the N-terminal unit remain elusive. Here, we show that N- and C-terminal cassettes adopt vastly different relative orientations in a crystal structure of BRR2 in complex with an activating domain of the spliceosomal Prp8 protein at 2.4 Å resolution compared with the crystal structure of BRR2 alone. Likewise, inspection of BRR2 structures within spliceosomal complexes revealed that the cassettes occupy different relative positions and engage in different intercassette contacts during different splicing stages. Engineered disulfide bridges that locked the cassettes in two different relative orientations had opposite effects on the RNA-unwinding activity of the N-terminal cassette, with one configuration enhancing and the other configuration inhibiting RNA unwinding compared with the unconstrained protein. Moreover, we found that differences in relative positioning of the cassettes strongly influence RNA-stimulated ATP hydrolysis by the N-terminal cassette. Our results indicate that the inactive C-terminal cassette of BRR2 can both positively and negatively affect the activity of the N-terminal helicase unit from a distance.

PubMed: 31914407
DOI: 10.1074/jbc.RA119.010964

実験手法

X-RAY DIFFRACTION (2.391 Å)