Description:
<jats:p>
<jats:italic>Escherichia coli</jats:italic> translational initiation factor IF1 was studied by <jats:sup>1</jats:sup>H‐NMR spectroscopy at 400 MHz. IF1 displays a very well resolved spectrum in both aromatic and aliphatic regions. Other spectral characteristics include relatively narrow resonance lines and lack of relevant cross‐relaxation phenomena. The resonances of the aromatic residues, in particular of the two His and two Tyr, were assigned by selective chemical modifications and spectroscopic techniques to individual residues in the protein sequence. The relative mobility of various residues of IF1 has been evaluated on the basis of the spin‐lattice relaxation times which are rather short and homogeneous. Overall the factor appears to have a complex secondary and tertiary structure and to be a flexible protein whose residues have a high degree of internal mobility.</jats:p>