title: Preliminary structural studies on MPN423 expressed from an orthologous ORFan of Mycoplasma pneumoniae.
abstract: ORFans are orphan open reading frames. The numbers of ORFans are steadfastly increasing despite of the genome database increment. Characterizing ORFans is essential to fully understanding the diversity of the structure and function of proteins in nature. In this study, MPN423 from Mycoplasma pneumoniae has been cloned, expressed, purified, and crystallized. MPN423 is an orthologous ORFan whose only known homologue in the whole genome database is MG296 from M. genitalium. X-ray diffraction data were collected to 2.7 A from the crystal of a selenomethionine substitute MPN423. The crystal belongs to the primitive monoclinic space group P2(1), with unit-cell parameters of a = 50.5 A, b = 89.2 A, c = 50.6 A, and beta = 102.9 degrees . A preliminary electron density map shows five alpha-helical segments per MPN423 molecule. A full structure determination is under way to provide helpful information to general questions about orthologous ORFan products.
authors.affiliation: College of Pharmacy, Ewha Womans University, Seoul 120-750, Korea. dhshin55@ewha.ac.kr.
authors.forename: Dong Hae
authors.initials: DH
authors.lastname: Shin
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics; D003001:Cloning, Molecular; D018360:Crystallography, X-Ray; D004926:Escherichia coli / Q000235:genetics; D015870:Gene Expression; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D015394:Molecular Structure; D009177:Mycoplasma pneumoniae / Q000737:chemistry* / Q000235:genetics; D016366:Open Reading Frames; D017433:Protein Structure, Secondary; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D055672:Static Electricity
chemical_list: D001426:Bacterial Proteins; D011993:Recombinant Fusion Proteins