Abstract
Rotaviruses, segmented double-stranded RNA viruses, co-opt the eukaryotic translation machinery with the aid of nonstructural protein 3 (NSP3), a rotaviral functional homolog of the cellular poly(A) binding protein (PABP). NSP3 binds to viral mRNA 3' consensus sequences and circularizes mRNA via interactions with eIF4G. Here, we present the X-ray structure of the C-terminal domain of NSP3 (NSP3-C) recognizing a fragment of eIF4GI. Homodimerization of NSP3-C yields a symmetric, elongated, largely alpha-helical structure with two hydrophobic eIF4G binding pockets at the dimer interface. Site-directed mutagenesis and isothermal titration calorimetry documented that NSP3 and PABP use analogous eIF4G recognition strategies, despite marked differences in tertiary structure.
Publication types
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Research Support, Non-U.S. Gov't
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Amino Acid Sequence
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Animals
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Binding Sites
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Carrier Proteins / chemistry
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Carrier Proteins / genetics
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Carrier Proteins / metabolism
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Dimerization
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Eukaryotic Initiation Factor-4G
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Humans
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Models, Molecular
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Molecular Sequence Data
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Peptide Initiation Factors / chemistry*
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Peptide Initiation Factors / metabolism
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Protein Structure, Quaternary
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RNA, Messenger / metabolism*
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RNA-Binding Proteins / chemistry
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RNA-Binding Proteins / metabolism
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Recombinant Fusion Proteins / chemistry
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Recombinant Fusion Proteins / genetics
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Recombinant Fusion Proteins / metabolism
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Sequence Alignment
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Viral Nonstructural Proteins / chemistry*
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Viral Nonstructural Proteins / metabolism
Substances
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Carrier Proteins
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Eukaryotic Initiation Factor-4G
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NSP3 protein, Rotavirus
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Peptide Initiation Factors
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RNA, Messenger
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RNA-Binding Proteins
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Recombinant Fusion Proteins
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Viral Nonstructural Proteins