4ILG

Crystal structure of Aar2p in complex with the Prp8p RNaseH and Jab1/MPN domains

Summary for 4ILG

• Entry DOI: 10.2210/pdb4ilg/pdb
• Related: 4ILH 4ILI 4ILJ
• Descriptor: A1 cistron-splicing factor AAR2, Pre-mRNA-splicing factor 8, 4-(2-HYDROXYETHYL)-1-PIPERAZINE ETHANESULFONIC ACID, ... (5 entities in total)
• Functional Keywords: u5 snrnp assembly, aar2, prp8, splicing
• Biological source: Saccharomyces cerevisiae (Baker's yeast); More
• Cellular location: Cytoplasm: P32357; Nucleus: P33334 P33334
• Total number of polymer chains: 3
• Total formula weight: 100449.62

Authors

Weber, G.,Heroven, A.C.,Santos, K.F.,Wahl, M.C. (deposition date: 2012-12-31, release date: 2013-03-13, Last modification date: 2023-09-20)

Primary citation

Weber, G.,Cristao, V.F.,Santos, K.F.,Jovin, S.M.,Heroven, A.C.,Holton, N.,Luhrmann, R.,Beggs, J.D.,Wahl, M.C.
Structural basis for dual roles of Aar2p in U5 snRNP assembly.
Genes Dev., 27:525-540, 2013

PubMed Abstract: Yeast U5 small nuclear ribonucleoprotein particle (snRNP) is assembled via a cytoplasmic precursor that contains the U5-specific Prp8 protein but lacks the U5-specific Brr2 helicase. Instead, pre-U5 snRNP includes the Aar2 protein not found in mature U5 snRNP or spliceosomes. Aar2p and Brr2p bind competitively to a C-terminal region of Prp8p that comprises consecutive RNase H-like and Jab1/MPN-like domains. To elucidate the molecular basis for this competition, we determined the crystal structure of Aar2p in complex with the Prp8p RNase H and Jab1/MPN domains. Aar2p binds on one side of the RNase H domain and extends its C terminus to the other side, where the Jab1/MPN domain is docked onto a composite Aar2p-RNase H platform. Known Brr2p interaction sites of the Jab1/MPN domain remain available, suggesting that Aar2p-mediated compaction of the Prp8p domains sterically interferes with Brr2p binding. Moreover, Aar2p occupies known RNA-binding sites of the RNase H domain, and Aar2p interferes with binding of U4/U6 di-snRNA to the Prp8p C-terminal region. Structural and functional analyses of phospho-mimetic mutations reveal how phosphorylation reduces affinity of Aar2p for Prp8p and allows Brr2p and U4/U6 binding. Our results show how Aar2p regulates both protein and RNA binding to Prp8p during U5 snRNP assembly.

PubMed: 23442228
DOI: 10.1101/gad.213207.113

Experimental method

X-RAY DIFFRACTION (2.1 Å)