title: ¹H, ¹³C and ¹⁵N chemical shift assignments of Na-FAR-1, a helix-rich fatty acid and retinol binding protein of the parasitic nematode Necator americanus.
abstract: The fatty acid and retinol-binding (FAR) proteins are a family of unusual helix-rich lipid binding proteins found exclusively in nematodes, and are secreted by a range of parasites of humans, animals and plants. Na-FAR-1 is from the parasitic nematode Necator americanus, an intestinal blood-feeding parasite of humans. Sequence-specific (1)H, (13)C and (15)N resonance assignments have been obtained for the recombinant 170 amino acid protein, using three-dimensional triple-resonance heteronuclear magnetic resonance experiments. Backbone assignments have been obtained for 99.3% of the non-proline HN/N pairs (146 out of 147). The amide resonance of T45 was not observed, probably due to rapid exchange with solvent water. A total of 96.9% of backbone resonances were identified, while 97.7% assignment of amino acid sidechain protons is complete. All Hα(166), Hβ(250) and Hγ(160) and 98.4% of the Hδ (126 out of 128) atoms were assigned. In addition, 99.4% Cα (154 out of 155) and 99.3% Cβ (143 out of 144) resonances have been assigned. No resonances were observed for the NH(n) groups of R93 NεHε, arginine, N(η1)H2, N(η2)H2, histidine N(δ1)H(δ1), N(ε1)H(ε1) and lysine N(ζ3)H3. Na-FAR-1 has a similar overall arrangement of α-helices to Ce-FAR-7 of the free-living Caeorhabditis elegans, but with an extra C-terminal helix.
authors.affiliation: Facultad de Ciencias Médicas, Instituto de Investigaciones Bioquímicas de La Plata, CONICET-UNLP, calles 60 y 120, 1900, La Plata, Argentina.
authors.forename: M Florencia
authors.initials: MF
authors.lastname: Rey-Burusco
authors.forename: Marina
authors.initials: M
authors.lastname: Ibañez-Shimabukuro
authors.forename: Alan
authors.initials: A
authors.lastname: Cooper
authors.forename: Malcolm W
authors.initials: MW
authors.lastname: Kennedy
authors.forename: Betina
authors.initials: B
authors.lastname: Córsico
authors.forename: Brian O
authors.initials: BO
authors.lastname: Smith
mesh_terms: D000818:Animals; D002247:Carbon Isotopes; D005227:Fatty Acids / Q000378:metabolism*; D015801:Helminth Proteins / Q000737:chemistry*; D006859:Hydrogen; D017221:Necator americanus / Q000378:metabolism*; D009587:Nitrogen Isotopes; D019906:Nuclear Magnetic Resonance, Biomolecular; D010271:Parasites / Q000378:metabolism*; D017433:Protein Structure, Secondary; D011994:Recombinant Proteins / Q000737:chemistry; D012177:Retinol-Binding Proteins / Q000737:chemistry*
chemical_list: D002247:Carbon Isotopes; D005227:Fatty Acids; D015801:Helminth Proteins; D009587:Nitrogen Isotopes; D011994:Recombinant Proteins; D012177:Retinol-Binding Proteins; D006859:Hydrogen