2LBW

Solution structure of the S. cerevisiae H/ACA RNP protein Nhp2p-S82W mutant

Summary for 2LBW

• Entry DOI: 10.2210/pdb2lbw/pdb
• Related: 2LBX
• NMR Information: BMRB: 17578
• Descriptor: H/ACA ribonucleoprotein complex subunit 2 (1 entity in total)
• Functional Keywords: l7ae, snornp, scarnp, rna binding protein
• Biological source: Saccharomyces cerevisiae (yeast)
• Cellular location: Nucleus, nucleolus: P32495
• Total number of polymer chains: 1
• Total formula weight: 13306.65

Authors

Koo, B.,Park, C.,Fernandez, C.F.,Chim, N.,Ding, Y.,Chanfreau, G.,Feigon, J. (deposition date: 2011-04-07, release date: 2011-07-06, Last modification date: 2024-05-01)

Primary citation

Koo, B.K.,Park, C.J.,Fernandez, C.F.,Chim, N.,Ding, Y.,Chanfreau, G.,Feigon, J.
Structure of H/ACA RNP Protein Nhp2p Reveals Cis/Trans Isomerization of a Conserved Proline at the RNA and Nop10 Binding Interface.
J.Mol.Biol., 411:927-942, 2011

PubMed Abstract: H/ACA small nucleolar and Cajal body ribonucleoproteins (RNPs) function in site-specific pseudouridylation of eukaryotic rRNA and snRNA, rRNA processing, and vertebrate telomerase biogenesis. Nhp2, one of four essential protein components of eukaryotic H/ACA RNPs, forms a core trimer with the pseudouridylase Cbf5 and Nop10 that binds to H/ACA RNAs specifically. Crystal structures of archaeal H/ACA RNPs have revealed how the protein components interact with each other and with the H/ACA RNA. However, in place of Nhp2p, archaeal H/ACA RNPs contain L7Ae, which binds specifically to an RNA K-loop motif absent from eukaryotic H/ACA RNPs, while Nhp2 binds a broader range of RNA structures. We report solution NMR studies of Saccharomyces cerevisiae Nhp2 (Nhp2p), which reveal that Nhp2p exhibits two major conformations in solution due to cis/trans isomerization of the evolutionarily conserved Pro83. The equivalent proline is in the cis conformation in all reported structures of L7Ae and other homologous proteins. Nhp2p has the expected α-β-α fold, but the solution structures of the major conformation of Nhp2p with trans Pro83 and of Nhp2p-S82W with cis Pro83 reveal that Pro83 cis/trans isomerization affects the positions of numerous residues at the Nop10 and RNA binding interface. An S82W substitution, which stabilizes the cis conformation, also stabilizes the association of Nhp2p with H/ACA snoRNPs expressed in vivo. We propose that Pro83 plays a key role in the assembly of the eukaryotic H/ACA RNP, with the cis conformation locking in a stable Cbf5-Nop10-Nhp2 ternary complex and positioning the protein backbone to interact with the H/ACA RNA.

PubMed: 21708174
DOI: 10.1016/j.jmb.2011.06.022

Experimental method

SOLUTION NMR