Sequence-specific 1H NMR resonance assignments of Bacillus subtilis HPr: use of spectra obtained from mutants to resolve spectral overlap.

On the basis of an analysis of two-dimensional 1H NMR spectra, the complete sequence-specific 1H NMR assignments are presented for the phosphocarrier protein HPr from the Gram-positive bacterium Bacillus subtilis. During the assignment procedure, extensive use was made of spectra obtained from point mutants of HPr in order to resolve spectral overlap and to provide verification of assignments. Regions of regular secondary structure were identified by characteristic patterns of sequential backbone proton NOEs and slowly exchanging amide protons. B. subtilis HPr contains four beta-strands that form a single antiparallel beta-sheet and two well-defined alpha-helices. There are two stretches of extended backbone structure, one of which contains the active site His15. The overall fold of the protein is very similar to that of Escherichia coli HPr determined by NMR studies [Klevit, R. E., & Waygood, E. B. (1986) Biochemistry 25, 7774-7781].