Figure 1.

 2D [¹H,¹⁵N]-HSQC spectrum of uniformly ¹⁵N-enriched Asl1650 (600 MHz, 303 K, protein concentration 2 mM in 20 mM sodium phosphate buffer at pH 6.0, 250 mM NaCl). Backbone ¹⁵N−¹H cross peaks are identified with the one-letter amino acid symbol and the sequence number; for side chain ¹⁵N−¹H correlations, the atom positions for Arg and Trp and horizontal lines for the −¹⁵N¹H₂ moieties of Asn and Gln are also indicated.