Linked Life Data

21708174

Source:http://linkedlifedata.com/resource/pubmed/id/21708174

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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2011-8-15
pubmed:databankReference
pubmed:abstractText
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 ?-?-? 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:grant
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
1089-8638
pubmed:author
pubmed:copyrightInfo
Copyright © 2011 Elsevier Ltd. All rights reserved.
pubmed:issnType
Electronic
pubmed:day
2
pubmed:volume
411
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
927-42
pubmed:meshHeading
pubmed-meshheading:21708174-Amino Acid Sequence, pubmed-meshheading:21708174-Amino Acid Substitution, pubmed-meshheading:21708174-Blotting, Western, pubmed-meshheading:21708174-Immunoprecipitation, pubmed-meshheading:21708174-Magnetic Resonance Spectroscopy, pubmed-meshheading:21708174-Models, Molecular, pubmed-meshheading:21708174-Molecular Sequence Data, pubmed-meshheading:21708174-Nuclear Proteins, pubmed-meshheading:21708174-Proline, pubmed-meshheading:21708174-Protein Binding, pubmed-meshheading:21708174-Protein Conformation, pubmed-meshheading:21708174-RNA, Fungal, pubmed-meshheading:21708174-RNA, Small Nucleolar, pubmed-meshheading:21708174-RNA-Binding Proteins, pubmed-meshheading:21708174-Ribonucleoproteins, Small Nuclear, pubmed-meshheading:21708174-Ribonucleoproteins, Small Nucleolar, pubmed-meshheading:21708174-Saccharomyces cerevisiae, pubmed-meshheading:21708174-Saccharomyces cerevisiae Proteins, pubmed-meshheading:21708174-Sequence Homology, Amino Acid, pubmed-meshheading:21708174-Stereoisomerism
pubmed:year
2011
pubmed:articleTitle
Structure of H/ACA RNP protein Nhp2p reveals cis/trans isomerization of a conserved proline at the RNA and Nop10 binding interface.
pubmed:affiliation
Department of Chemistry and Biochemistry, and the Molecular Biology Institute, PO Box 951569,University of California, Los Angeles, CA 90095-1569, USA.
pubmed:publicationType
Journal Article, Research Support, N.I.H., Extramural