title: Solution NMR and X-ray crystal structures of membrane-associated Lipoprotein-17 domain reveal a novel fold.
abstract: The conserved Lipoprotein-17 domain of membrane-associated protein Q9PRA0_UREPA from Ureaplasma parvum was selected for structure determination by the Northeast Structural Genomics Consortium, as part of the Protein Structure Initiative's program on structure-function analysis of protein domains from large domain sequence families lacking structural representatives. The 100-residue Lipoprotein-17 domain is a "domain of unknown function" (DUF) that is a member of Pfam protein family PF04200, a large domain family for which no members have characterized biochemical functions. The three-dimensional structure of the Lipoprotein-17 domain of protein Q9PRA0_UREPA was determined by both solution NMR and by X-ray crystallography at 2.5 Å. The two structures are in good agreement with each other. The domain structure features three α-helices, α1 through α3, and five β-strands. Strands β1/β2, β3/β4, β4/β5 are anti-parallel to each other. Strands β1and β2 are orthogonal to strands β3, β4, β5, while helix α3 is formed between the strands β3 and β4. One-turn helix α2 is formed between the strands β1 and β2, while helix α1 occurs in the N-terminal polypeptide segment. Searches of the Protein Data Bank do not identify any other protein with significant structural similarity to Lipoprotein-17 domain of Q9PRA0_UREPA, indicating that it is a novel protein fold.
authors.affiliation: Center for Advanced Biotechnology and Medicine, Department of Molecular Biology and Biochemistry, Rutgers, The State University of New Jersey, Piscataway, 08854, USA.
authors.forename: Rajeswari
authors.initials: R
authors.lastname: Mani
authors.forename: Sergey
authors.initials: S
authors.lastname: Vorobiev
authors.forename: G V T
authors.initials: GV
authors.lastname: Swapna
authors.forename: Helen
authors.initials: H
authors.lastname: Neely
authors.forename: Haleema
authors.initials: H
authors.lastname: Janjua
authors.forename: Colleen
authors.initials: C
authors.lastname: Ciccosanti
authors.forename: Rong
authors.initials: R
authors.lastname: Xiao
authors.forename: Thomas B
authors.initials: TB
authors.lastname: Acton
authors.forename: John K
authors.initials: JK
authors.lastname: Everett
authors.forename: John
authors.initials: J
authors.lastname: Hunt
authors.forename: Gaetano T
authors.initials: GT
authors.lastname: Montelione
mesh_terms: D000595:Amino Acid Sequence; D018360:Crystallography, X-Ray; D008074:Lipoproteins / Q000737:chemistry*; D008565:Membrane Proteins / Q000737:chemistry*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009174:Mycoplasma / Q000378:metabolism; D019906:Nuclear Magnetic Resonance, Biomolecular; D011487:Protein Conformation; D017510:Protein Folding; D017434:Protein Structure, Tertiary; D012996:Solutions; D014509:Ureaplasma / Q000378:metabolism*
chemical_list: D008074:Lipoproteins; D008565:Membrane Proteins; D012996:Solutions