3SBS

Crystal structure of Aar2 protein

Summary for 3SBS

• Entry DOI: 10.2210/pdb3sbs/pdb
• Related: 3SBG 3SBT
• Descriptor: A1 cistron-splicing factor AAR2 (2 entities in total)
• Functional Keywords: vhs like domain, splicing
• Biological source: Saccharomyces cerevisiae (Baker's yeast)
• Cellular location: Cytoplasm: P32357
• Total number of polymer chains: 1
• Total formula weight: 42805.82

Authors

Weber, G.,Santos, K.F.,Holton, N.,Wahl, M.C. (deposition date: 2011-06-06, release date: 2012-04-18, Last modification date: 2024-02-28)

Primary citation

Weber, G.,Cristao, V.F.,de L Alves, F.,Santos, K.F.,Holton, N.,Rappsilber, J.,Beggs, J.D.,Wahl, M.C.
Mechanism for Aar2p function as a U5 snRNP assembly factor.
Genes Dev., 25:1601-1612, 2011

PubMed Abstract: Little is known about how particle-specific proteins are assembled on spliceosomal small nuclear ribonucleoproteins (snRNPs). Brr2p is a U5 snRNP-specific RNA helicase required for spliceosome catalytic activation and disassembly. In yeast, the Aar2 protein is part of a cytoplasmic precursor U5 snRNP that lacks Brr2p and is replaced by Brr2p in the nucleus. Here we show that Aar2p and Brr2p bind to different domains in the C-terminal region of Prp8p; Aar2p interacts with the RNaseH domain, whereas Brr2p interacts with the Jab1/MPN domain. These domains are connected by a long, flexible linker, but the Aar2p-RNaseH complex sequesters the Jab1/MPN domain, thereby preventing binding by Brr2p. Aar2p is phosphorylated in vivo, and a phospho-mimetic S253E mutation in Aar2p leads to disruption of the Aar2p-Prp8p complex in favor of the Brr2p-Prp8p complex. We propose a model in which Aar2p acts as a phosphorylation-controlled U5 snRNP assembly factor that regulates the incorporation of the particle-specific Brr2p. The purpose of this regulation may be to safeguard against nonspecific RNA binding to Prp8p and/or premature activation of Brr2p activity.

PubMed: 21764848
DOI: 10.1101/gad.635911

Experimental method

X-RAY DIFFRACTION (2.1 Å)