title: Solution structure and dynamics of the reduced and oxidized forms of the N-terminal domain of PilB from Neisseria meningitidis.
abstract: The secreted form of the PilB protein was proposed to be involved in pathogen survival fighting against the defensive host's oxidative burst. PilB protein is composed of three domains. The central and the C-terminal domains display methionine sulfoxide reductase A and B activities, respectively. The N-terminal domain, which possesses a CXXC motif, was recently shown to regenerate in vitro the reduced forms of the methionine sulfoxide reductase domains of PilB from their oxidized forms, as does the thioredoxin 1 from E. coli, via a disulfide bond exchange. The thioredoxin-like N-terminal domain belongs to the cytochrome maturation protein structural family, but it possesses a unique additional segment (99)FLHE (102) localized in a loop. This segment covers one edge of the active site in the crystal structure of the reduced form of the N-terminal domain of PilB. We have determined the solution structure and the dynamics of the N-terminal domain from Neisseria meningitidis, in its reduced and oxidized forms. The FLHE loop adopts, in both redox states, a well-defined conformation. Subtle conformational and dynamic changes upon oxidation are highlighted around the active site, as well as in the FLHE loop. The functional consequences of the cytochrome maturation protein topology and those of the presence of FLHE loop are discussed in relation to the enzymatic properties of the N-terminal domain.
authors.affiliation: Laboratoire de Chimie Physique Macromoléculaire, UMR 7568 CNRS-INPL, Nancy Université, 1 rue Grandville, B.P. 20451, 54001 Nancy Cedex, France.
authors.forename: Marc
authors.initials: M
authors.lastname: Quinternet
authors.forename: Pascale
authors.initials: P
authors.lastname: Tsan
authors.forename: Fabrice
authors.initials: F
authors.lastname: Neiers
authors.forename: Chrystel
authors.initials: C
authors.lastname: Beaufils
authors.forename: Sandrine
authors.initials: S
authors.lastname: Boschi-Muller
authors.forename: Marie-Christine
authors.initials: MC
authors.lastname: Averlant-Petit
authors.forename: Guy
authors.initials: G
authors.lastname: Branlant
authors.forename: Manh-Thong
authors.initials: MT
authors.lastname: Cung
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D009345:Neisseria meningitidis / Q000378:metabolism*; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000737:chemistry* / Q000378:metabolism*; D011487:Protein Conformation; D017434:Protein Structure, Tertiary
chemical_list: D001426:Bacterial Proteins; D010088:Oxidoreductases; C068255:pilB protein, Bacteria