1H, 15N, and 13C NMR signal assignments of IIIGlc, a signal-transducing protein of Escherichia coli, using three-dimensional triple-resonance techniques.
IIIGlc is an 18.1-kDa signal-transducing phosphocarrier protein of the phosphoenolpyruvate:glycose phosphotransferase system (PTS) of Escherichia coli. Virtually complete (98%) backbone 1H, 15N, and 13C nuclear magnetic resonance (NMR) signal assignments were determined by using a battery of triple-resonance three-dimensional (3D) NMR pulse sequences. In addition, nearly complete (1H, 95%; 13C, 85%) side-chain 1H and 13C signal assignments were obtained from an analysis of 3D 13C HCCH-COSY and HCCH-TOCSY spectra. These experiments rely almost exclusively upon one- and two-bond J couplings to transfer magnetization and to correlate proton and heteronuclear NMR signals. Hence, essentially complete signal assignments of this 168-residue protein were made without any assumptions regarding secondary structure and without the aid of a crystal structure, which is not yet available. Moreover, only three samples, one uniformly 15N-enriched, one uniformly 15N/13C-enriched, and one containing a few types of amino acids labeled with 15N and/or 13C, were needed to make the assignments. The backbone assignments together with the 3D 15N NOESY-HMQC and 13C NOESY-HMQC data have provided extensive information about the secondary structure of this protein [Pelton, J.G., Torchia, D.A., Meadow, N.D., Wong, C.-Y., & Roseman, S (1991) Proc. Natl. Acad. Sci. U.S.A. 88, 3479-3488]. The nearly complete set of backbone and side-chain atom assignments reported herein provide a basis for studies of the three-dimensional structure and dynamics of IIIGlc as well as its interactions with a variety of membrane and cytoplasmic proteins.
Pelton
J G
JG
Bone Research Branch, National Institute of Dental Research, Bethesda, Maryland 20892.
Torchia
D A
DA
Meadow
N D
ND
Wong
C Y
CY
Roseman
S
S
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry*; D004926:Escherichia coli / Q000737:chemistry*; D029968:Escherichia coli Proteins; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System / Q000737:chemistry*; D011487:Protein Conformation; D015398:Signal Transduction
D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; C032242:crr protein, E coli; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System