title: Solution structure of HI1506, a novel two-domain protein from Haemophilus influenzae.
abstract: HI1506 is a 128-residue hypothetical protein of unknown function from Haemophilus influenzae. It was originally annotated as a shorter 85-residue protein, but a more detailed sequence analysis conducted in our laboratory revealed that the full-length protein has an additional 43 residues on the C terminus, corresponding with a region initially ascribed to HI1507. As part of a larger effort to understand the functions of hypothetical proteins from Gram-negative bacteria, and H. influenzae in particular, we report here the three-dimensional solution NMR structure for the corrected full-length HI1506 protein. The structure consists of two well-defined domains, an alpha/beta 50-residue N-domain and a 3-alpha 32-residue C-domain, separated by an unstructured 30-residue linker. Both domains have positively charged surface patches and weak structural homology with folds that are associated with RNA binding, suggesting a possible functional role in binding distal nucleic acid sites.
authors.affiliation: Center for Advanced Research in Biotechnology, University of Maryland Biotechnology Institute, Rockville, Maryland 20850, USA.
authors.forename: Nese
authors.initials: N
authors.lastname: Sari
authors.forename: Yanan
authors.initials: Y
authors.lastname: He
authors.forename: Victoria
authors.initials: V
authors.lastname: Doseeva
authors.forename: Karen
authors.initials: K
authors.lastname: Surabian
authors.forename: Jayanthi
authors.initials: J
authors.lastname: Ramprakash
authors.forename: Fred
authors.initials: F
authors.lastname: Schwarz
authors.forename: Osnat
authors.initials: O
authors.lastname: Herzberg
authors.forename: John
authors.initials: J
authors.lastname: Orban
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics; D002152:Calorimetry, Differential Scanning; D006193:Haemophilus influenzae / Q000235:genetics / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008969:Molecular Sequence Data; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D017386:Sequence Homology, Amino Acid; D012996:Solutions
chemical_list: D001426:Bacterial Proteins; D012996:Solutions