title: Crystal structure of an enhancer of rudimentary homolog (ERH) at 2.1 Angstroms resolution.
abstract: The enhancer of rudimentary gene, e(r), of Drosophila melanogaster encodes an enhancer of rudimentary (ER) protein with functions implicated in pyrimidine biosynthesis and the cell cycle. The ER homolog (ERH) is highly conserved among vertebrates, invertebrates, and plants. Xenopus laevis ERH was reported to be a transcriptional repressor. Here we report the 2.1 Angstroms crystal structure of murine ERH (Protein Data Bank ID 1WZ7), determined by the multiwavelength anomalous dispersion (MAD) method. The monomeric structure of ERH comprises a single domain consisting of three alpha-helices and four beta-strands, which is a novel fold. In the crystal structure, ERH assumes a dimeric structure, through interactions between the beta-sheet regions. The formation of an ERH dimer is consistent with the results of analytical ultracentrifugation. The residues at the core region and at the dimer interface are highly conserved, suggesting the conservation of the dimer formation as well as the monomer fold. The long flexible loop (44 approximately 53) is also significantly conserved, suggesting that this loop region may be important for the functions of ERH. In addition, the putative phosphorylation sites are located at the start of the beta2-strand (Thr18) and at the start of the alpha1-helix (Ser24), implying that the phosphorylation might cause some structural changes.
authors.affiliation: Protein Research Group, RIKEN Yokohama Institute, Tsurumi-ku, Yokohama, Japan.
authors.forename: Ryoichi
authors.initials: R
authors.lastname: Arai
authors.forename: Mutsuko
authors.initials: M
authors.lastname: Kukimoto-Niino
authors.forename: Hiroko
authors.initials: H
authors.lastname: Uda-Tochio
authors.forename: Satoshi
authors.initials: S
authors.lastname: Morita
authors.forename: Tomomi
authors.initials: T
authors.lastname: Uchikubo-Kamo
authors.forename: Ryogo
authors.initials: R
authors.lastname: Akasaka
authors.forename: Yuuka
authors.initials: Y
authors.lastname: Etou
authors.forename: Yoshihide
authors.initials: Y
authors.lastname: Hayashizaki
authors.forename: Takanori
authors.initials: T
authors.lastname: Kigawa
authors.forename: Takaho
authors.initials: T
authors.lastname: Terada
authors.forename: Mikako
authors.initials: M
authors.lastname: Shirouzu
authors.forename: Shigeyuki
authors.initials: S
authors.lastname: Yokoyama
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D018797:Cell Cycle Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D017124:Conserved Sequence; D018360:Crystallography, X-Ray; D019281:Dimerization; D051379:Mice; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010766:Phosphorylation; D011487:Protein Conformation; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism
chemical_list: D018797:Cell Cycle Proteins; C484496:ERH protein, mouse; D014157:Transcription Factors