Senn, H.Eugster, A.Otting, G.Suter, F.Wüthrich, K.2026-03-232026-03-230175-7571PubMed:3552643ORCID:/0000-0002-0563-0146/work/209074927https://hdl.handle.net/1885/733807621The salmonella phage P22 c2 repressor was produced with 90% 15N isotope labeling of all leucines, using the expression system E. coli W3110 lac IQ/pTP 125. The N-terminal DNA-binding domain 1-76 was obtained by chymotrypsin cleavage. Its characterization by biochemical techniques, mass spectrometry, and one- and two-dimensional nuclear magnetic resonance (NMR) showed that highly residue-selective isotope labeling was achieved with the minimal growth medium used. The ability to obtain such isotope labeling opens new avenues for NMR studies of protein-DNA interactions in the P22 operator system.6enIsotope labelingnuclear magnetic resonanceP22c2 repressorprotein conformationprotein-DNA interactions198710.1007/BF002548950023084280