title: ¹H, ¹³C, ¹⁵N backbone and side chain NMR resonance assignments of the N-terminal NEAr iron transporter domain 1 (NEAT 1) of the hemoglobin receptor IsdB of Staphylococcus aureus.
abstract: Staphylococcus aureus is an opportunistic pathogen that causes skin and severe infections in mammals. Critical to S. aureus growth is its ability to scavenge iron from host cells. To this effect, S. aureus has evolved a sophisticated pathway to acquire heme from hemoglobin (Hb) as a preferred iron source. The pathway is comprised of nine iron-regulated surface determinant (Isd) proteins involved in heme capture, transport, and degradation. A key protein of the heme acquisition pathway is the surface-anchored hemoglobin receptor protein IsdB, which is comprised of two NEAr transporter (NEAT) domains that act in concert to bind Hb and extract heme for subsequent transfer to downstream acquisition pathway proteins. Despite significant advances in the structural knowledge of other Isd proteins, the structural mechanisms and molecular basis of the IsdB-mediated heme acquisition process are not well understood. In order to provide more insights into the mode of function of IsdB, we have initiated NMR structural studies of the first NEAT domain of IsdB (IsdB(N1)). Herein, we report the near complete (1)H, (13)C and (15)N resonance assignments of backbone and side chain atoms, and the secondary structural topology of the 148-residue IsdB NEAT 1 domain. The NMR results are consistent with the presence of eight β-strands and one α-helix characteristic of an immunoglobulin-like fold observed in other NEAT domain family proteins. This work provides a solid framework to obtain atomic-level insights toward understanding how IsdB mediates IsdB-Hb protein-protein interactions critical for heme capture and transfer.
authors.affiliation: Department of Chemistry and Biochemistry, Montana State University, 103 Chemistry and Biochemistry Building, PO Box 173400, Bozeman, MT, 59717-3400, USA.
authors.forename: Brittany A
authors.initials: BA
authors.lastname: Fonner
authors.forename: Brian P
authors.initials: BP
authors.lastname: Tripet
authors.forename: Mengyao
authors.initials: M
authors.lastname: Lui
authors.forename: Hui
authors.initials: H
authors.lastname: Zhu
authors.forename: Benfang
authors.initials: B
authors.lastname: Lei
authors.forename: Valérie
authors.initials: V
authors.lastname: Copié
mesh_terms: D002247:Carbon Isotopes; D027682:Cation Transport Proteins / Q000737:chemistry*; D006454:Hemoglobins / Q000378:metabolism*; D006859:Hydrogen; D009587:Nitrogen Isotopes; D019906:Nuclear Magnetic Resonance, Biomolecular; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D011956:Receptors, Cell Surface / Q000737:chemistry*; D013211:Staphylococcus aureus / Q000378:metabolism*
chemical_list: D002247:Carbon Isotopes; D027682:Cation Transport Proteins; D006454:Hemoglobins; C510010:IsdB protein, Staphylococcus aureus; D009587:Nitrogen Isotopes; D011956:Receptors, Cell Surface; D006859:Hydrogen