title: Structure of Pseudomonas aeruginosa Hfq protein.
abstract: The structure of the Hfq protein from Pseudomonas aeruginosa was determined using two different ionic conditions. In both cases the molecules formed identical hexameric rings, but some variations in the crystal packing were revealed. Hfq belongs to the family of Sm/LSm proteins, the members of which can form hexameric as well as heptameric rings. Comparative analysis of known structures of this protein family shows that the fragment of the Sm-fold responsible for oligomerization is strongly structurally conserved. In the heptameric ring, three conserved hydrogen bonds between beta-strands of adjacent molecules hold together the monomers, whereas in the hexameric rings of Hfq an additional conserved inaccessible hydrogen bond between neighbouring monomers is observed.
authors.affiliation: Institute of Protein Research, Russian Academy of Sciences, 142290 Pushchino, Moscow Region, Russia. nikulin@vega.protres.ru
authors.forename: Alexey
authors.initials: A
authors.lastname: Nikulin
authors.forename: Elena
authors.initials: E
authors.lastname: Stolboushkina
authors.forename: Anna
authors.initials: A
authors.lastname: Perederina
authors.forename: Ioulia
authors.initials: I
authors.lastname: Vassilieva
authors.forename: Udo
authors.initials: U
authors.lastname: Blaesi
authors.forename: Isabella
authors.initials: I
authors.lastname: Moll
authors.forename: Galina
authors.initials: G
authors.lastname: Kachalova
authors.forename: Shigeyuki
authors.initials: S
authors.lastname: Yokoyama
authors.forename: Dmitry
authors.initials: D
authors.lastname: Vassylyev
authors.forename: Maria
authors.initials: M
authors.lastname: Garber
authors.forename: Stanislav
authors.initials: S
authors.lastname: Nikonov
mesh_terms: D000595:Amino Acid Sequence; D001704:Biopolymers / Q000737:chemistry; D003001:Cloning, Molecular; D018360:Crystallography, X-Ray; D035001:Host Factor 1 Protein / Q000737:chemistry* / Q000235:genetics; D008969:Molecular Sequence Data; D011487:Protein Conformation; D011550:Pseudomonas aeruginosa / Q000737:chemistry* / Q000235:genetics; D017386:Sequence Homology, Amino Acid
chemical_list: D001704:Biopolymers; D035001:Host Factor 1 Protein