title: Solution structure of the R3H domain from human Smubp-2.
abstract: The R3H domain is a conserved sequence motif, identified in over 100 proteins, that is thought to be involved in polynucleotide-binding, including DNA, RNA and single-stranded DNA. In this work the 3D structure of the R3H domain from human Smubp-2 was determined by NMR spectroscopy. It is the first 3D structure determination of an R3H domain. The fold presents a small motif, consisting of a three-stranded antiparallel beta-sheet and two alpha-helices, which is related to the structures of the YhhP protein and the C-terminal domain of the translational initiation factor IF3. The similarities are non-trivial, as the amino acid identities are below 10%. Three conserved basic residues cluster on the same face of the R3H domain and could play a role in nucleic acid recognition. An extended hydrophobic area at a different site of the molecular surface could act as a protein-binding site. A strong correlation between conservation of hydrophobic amino acids and side-chain solvent protection indicates that the structure of the Smubp-2 R3H domain is representative of R3H domains in general.
authors.affiliation: Department of Medical Biochemistry and Biophysics, Karolinska Institute, S-17177, Stockholm, Sweden
authors.forename: Edvards
authors.initials: E
authors.lastname: Liepinsh
authors.forename: Ainars
authors.initials: A
authors.lastname: Leonchiks
authors.forename: Anatoly
authors.initials: A
authors.lastname: Sharipo
authors.forename: Laurent
authors.initials: L
authors.lastname: Guignard
authors.forename: Gottfried
authors.initials: G
authors.lastname: Otting
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000378:metabolism; D029968:Escherichia coli Proteins; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D019906:Nuclear Magnetic Resonance, Biomolecular; D039665:Prokaryotic Initiation Factor-3 / Q000737:chemistry; D017434:Protein Structure, Tertiary; D016415:Sequence Alignment; D012996:Solutions; D013329:Structure-Activity Relationship; D014157:Transcription Factors / Q000737:chemistry* / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; C489892:IGHMBP2 protein, human; D039665:Prokaryotic Initiation Factor-3; C111946:SirA protein, E coli; D012996:Solutions; D014157:Transcription Factors