title: 1H, 15N and 13C NMR assignments, secondary structure and overall topology of the Escherichia coli GlgS protein.
abstract: GlgS is a 7892-Da protein which is involved in glycogen biosynthesis in bacteria. We report the 1H, 15N and 13C NMR assignments of the backbone and side-chain resonances at 25 degrees C and pH 6.7 from two-dimensional homonuclear and three-dimensional heteronuclear NMR experiments. The secondary structure of the protein was determined using sequential and medium-range NOE correlations, vicinal 3J(NH-H alpha) coupling values and amide proton exchange rates. The secondary structure obtained is consistent with the secondary chemical shifts of 1H alpha, 13C alpha and 13C = O. It was found that the secondary structure of GlgS comprises two amphipathic helices (Asn10-Met21 and Glu39-Arg60), one short highly hydrophobic helix (Ile30-Val33), a short extended beta-strand-like fragment (Arg26-Asp29) and two type I beta-turns (His22-Gly25 and Thr34-Met37). An overall topology of GlgS is suggested based on long-range NOEs. The elements of secondary structure form a sandwich in which the beta-strand and the short hydrophobic helix are positioned between the two amphipathic helices.
authors.affiliation: Department of Biochemistry and Montreal Joint Centre for Structural Biology, McGill University, QC, Canada.
authors.forename: N
authors.initials: N
authors.lastname: Beglova
authors.forename: D
authors.initials: D
authors.lastname: Fischer
authors.forename: R
authors.initials: R
authors.lastname: Hengge-Aronis
authors.forename: K
authors.initials: K
authors.lastname: Gehring
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000302:isolation & purification; D002247:Carbon Isotopes; D002850:Chromatography, Gel; D004926:Escherichia coli / Q000737:chemistry*; D029968:Escherichia coli Proteins; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D009587:Nitrogen Isotopes; D017433:Protein Structure, Secondary; D011522:Protons; D011994:Recombinant Proteins / Q000737:chemistry / Q000302:isolation & purification
chemical_list: D001426:Bacterial Proteins; D002247:Carbon Isotopes; D029968:Escherichia coli Proteins; C098049:GlgS protein, E coli; D009587:Nitrogen Isotopes; D011522:Protons; D011994:Recombinant Proteins