Fig. 2.

a 2D ¹H, ¹⁵N-HSQC spectrum of BilRI. The peaks are labeled with residue numbers and one-letter amino acid codes. Crosses indicate peaks found at lower contour levels. Residue numbering corresponds to that of whole BilRI protein (1–181) although the construct used was shorter (21–181). b 2D CON spectrum of BilRI. The peaks are labeled with residue number and amino acid code of the amide nitrogen in the C′-N^H pair. The peak of the only proline of the BilRI amino acid sequence, which resonates at 172.8 (²⁶Ser C′), 138.1 (²⁷Pro N^H) ppm is not shown. Asterisks indicate impurities. Both 2D spectra were acquired at 800 MHz ¹H frequency, 25 °C from a 1 mM BilRI sample at pH 6.5